Processing hydroxy-carboxylic acids to polymers

ABSTRACT

Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful intermediates and products, such as aliphatic hydroxy-carboxylic acid and hydroxyl-carboxylic acid derivatives. These aliphatic hydroxy-carboxylic acids are, in turn, polymerized. The polymerization is carried out using a thin film evaporator or a thin film polymerization/devolatilization device. Conversion of lactic acid to poly lactic acid is an especially useful product to this process.

This application incorporates by reference the full disclosure of thefollowing co-pending provisional application: U.S. Ser. No. 61/816,664,filed Apr. 26, 2013 and the co-pending provisional application: U.S.Ser. No. 61/941,771 filed Feb. 19, 2014.

BACKGROUND OF THE INVENTION

Many potential lignocellulosic feedstocks are available today, includingagricultural residues, woody biomass, municipal waste, oilseeds/cakesand seaweed, to name a few. At present, these materials are oftenunder-utilized, being used, for example, as animal feed, biocompostmaterials, burned in a co-generation facility or even landfilled.

Lignocellulosic biomass includes crystalline cellulose fibrils embeddedin a hemicellulose matrix, surrounded by lignin. This produces a compactmatrix that is difficult to access by enzymes and other chemical,biochemical and/or biological processes. Cellulosic biomass materials(e.g., biomass material from which the lignin has been removed) is moreaccessible to enzymes and other conversion processes, but even so,naturally-occurring cellulosic materials often have low yields (relativeto theoretical yields) when contacted with hydrolyzing enzymes.Lignocellulosic biomass is even more recalcitrant to enzyme attack.Furthermore, each type of lignocellulosic biomass has its own specificcomposition of cellulose, hemicellulose and lignin.

SUMMARY

Generally, this disclosure relates to methods and processes forconverting a material, such as a biomass feedstock, e.g., cellulosic,starchy or lignocellulosic materials, to useful products, for example,hydroxy-carboxylic acids (e.g., alpha, beta, gamma and deltahydroxy-carboxylic acids) and derivatives of hydroxy-carboxylicacid(e.g., esters). Then, in turn, the hydroxy-carboxylic acid ispolymerized to poly hydroxy-carboxylic acids. Such hydroxy-carboxylicacids can be poly-hydroxy-carboxylic acids, e.g. di-, tri-, tetra-,penta-, hexa- hepta- and octa-hydroxy carboxylic acids. Thepoly-hydroxy-carboxylic acid can be substituted with other groups, e.g.,alkyl groups. The carbon chain of the carboxylic acid may be straightchained, branched, cyclic, or alicyclic.

Among the important products that can be produced from lignocellulosicbiomass are hydroxy-carboxylic acids. These acids, e.g., the alpha, betaand gamma hydroxyl substituted acids can be polymerized to produceimportant polymers. The methyl substituted alpha acid, D-lactic acidand/or L-lactic acid, is commercially produced and polymerized topolylactic acid. This polymer is an important in that it can be producedin forms such that it can be spun into fibers, extruded into solidproducts and other products that require complex polymer processing.Since polylactic acid and the other polymers of alpha, beta, gamma anddelta hydroxy-carboxylic acids are biodegradable they offer interesttarget polymers for the bioprocessing industry. The most prevalentprocess to produce polylactic acid involves converting of the lacticacid to an oligomer, depolymerizing to obtain lactide dimer andpolymerizing that molecule. There is still a need for processing thatinvolves a more direct synthesis of the polymerized product withoutisolation of intermediates.

A method of making a high molecular weight polymer or copolymer e.g.,from oligomer, the method comprising evaporating water as it is formedduring condensation of a hydroxy-carboxylic acid polymer e.g. anoligomer or a polymer, as it traverses a surface of a thin filmpolymerization/devolatilization device. Where the hydroxy carboxylicacid has stereocenters, the stereocenters can be maintained during thepolymerization process. In some instances, the hydroxy-carboxylic acidis an aliphatic hydroxy-carboxylic. For instance, D-lactic acid and/orL-lactic acid become polymers of D-lactic acid and/or polymers ofL-lactic acid respectively, with little loss of stereo integrity. It isunderstood that the process described herein preserves thestereochemistry where the biochemistry and chemical processes preservethe stereochemistry. If both the D and L isomer monomer is listed it isunderstood that the D isomer monomer will become a D polymer and the Lisomer monomer will become a D polymer. When a hydroxy-carboxylic acidis listed without its stereochemistry it is understood that D, L, meso,and/or mixtures are assumed.

In another embodiment, a copolymer of a hydroxy-carboxylic polymer canbe a copolymer of the hydroxy-carboxylic acid monomers and othercompatible monomers. The copolymer can be a copolymer from differenthydroxy-carboxylic acid monomers, e.g., a mixture of lactic acid andanother 3-hydroxy butyric acid. The copolymer can also be obtained fromcopolymerizing oligomers of different hydroxy-carboxylic acids.

In a particular embodiment, a method of making poly aliphatichydroxy-carboxylic acids by the conversion of a crude aliphatichydroxy-carboxylic monomer to a poly aliphatic hydroxy-carboxylic acids,comprising the steps of:

-   -   a) providing a source of monomer as aliphatic hydroxy-carboxylic        acid in a hydroxylic medium;    -   b) concentrating the aliphatic hydroxy-carboxylic acid in the        hydroxylic medium by evaporating a substantial portion of the        hydroxylic medium to form a concentrated acid solution;    -   c) oligomerizing the aliphatic hydroxy-carboxylic acid to obtain        an aliphatic hydroxy-carboxylic acid oligomer with a degree of        oligomerization from about 5 to about 50;    -   d) adding a polymerization catalyst to the hydroxyl-carboxylic        acid oligomer;    -   e) polymerizing the aliphatic hydroxy-carboxylic acid and        aliphatic hydroxy-carboxylic acid oligomer to obtain a poly        aliphatic hydroxy-carboxylic acid with a degree of        polymerization of about 35 to about;    -   f) transferring the poly aliphatic hydroxy-carboxylic acid to a        thin film polymerization/devolatilization device to obtain a        degree of polymerization of about 300 to about 20,000;    -   g) isolating the poly aliphatic hydroxy-carboxylic acid and        wherein for steps d, e, f, and g cyclic dimers derived from the        aliphatic hydroxy-carboxylic acid are less than 10 weight        percent based on the total mass of the aliphatic        hydroxy-carboxylic acids monomers, oligomers and polymers. The        thin film polymerization/devolatilization device is configured        such that fluid polymer is conveyed to the device such that the        film of the fluid polymer is less than 1 cm thick and provides a        means for volatilizing the water formed in the reaction and        other volatile components. The temperature of the thin film        evaporator and polymerization/devolatilization device are from        100 to 240° C. and the pressure of the device is from 0.000014        to 50 kPa. A full vacuum may be used in the evaporator device.        Pressures can be e.g., less than 0.01 torr, alternatively less        than 0.001 torr and optionally less than 0.0001 torr.

The polymerization steps c, e, and f are three polymerization stages, 1,2 and 3, of polymerization of the aliphatic hydroxy-carboxylic acids.

The thin film evaporator or thin film polymerization/devolatilizationdevice are also a convenient place to add other components to the polyaliphatic hydroxy-carboxylic acids. These other components can includeother monomers including the aliphatic hydroxy-carboxylic acids,homologues of the aliphatic hydroxy-carboxylic acids, diols,dicarboxylic acids, alcohol amines, diamines and similar reactivespecies. Reactive components such as peroxides, glycidyl acrylates,epoxides and the like can also be added at this stage in the process.

An extruder also can be in fluid contact or fluid communications withthe thin film evaporator and/or thin filmpolymerization/devolatilization device and can be used to recycle thepolymer and/or to provide the means to process the polyhydroxy-carboxylic acid to the isolation portion of the process. Theextruder is also a convenient device to add other components andreactives listed above and discussed below, especially if they would bevolatilized in the thin film polymerization/devolatilization device. Inone aspect, the disclosure relates to a method for making a productincluding treating a reduced recalcitrance biomass (e.g.,lignocellulosic or cellulosic material) with one or more enzymes and/ororganisms to produce a hydroxyl-carboxylic acid (e.g., an alpha, beta,gamma or delta hydroxyl-carboxylic acid) and converting thehydroxyl-carboxylic acid to the product.

Optionally, the feedstock is pretreated with at least one methodselected from irradiation (e.g., with an electron beam), heat treatment,sonication, oxidation, pyrolysis and steam explosion, for example, toreduce the recalcitrance lignocellulosic or cellulosic material. In oneimplementation of the method, the hydroxyl-carboxylic acid is convertedchemically, for example, by converting D-lactic acid and/or L-lacticacid to esters by treating with an alcohol and an acid catalyst. Othermethods of chemically converting that can be utilized includepolymerization, isomerization, esterification, oxidation, reduction,disproportionation and combinations of these. Some examples ofhydroxy-carboxylic acids that can be produced and then further convertedinclude glycolic acid, lactic acid, malic acid, citric acid, andtartaric acid (di substituted), 3-hydroxybutyric acid (betasubstituted), 4-hydroxybutyric acid (gamma substituted), 3hydroxyvaleric acid (beta substituted), gluconic acid (tetra substitutedat alpha, beta, gamma, and delta carbons with an additional hydroxy atthe epsilon carbon).

In some other implementation, the lignocellulosic or cellulosic materialis treated with one of more enzymes to release one or more sugars; forexample, to release glucose, xylose, sucrose, maltose, lactose, mannose,galactose, arabinose, fructose, dimers of these such as cellobiose,heterodimers of these such as sucrose, oligomers of these, and mixturesof these. Optionally, treating can further include (e.g., subsequentlyto releasing sugars) utilizing (e.g., by contacting with the sugarsand/or biomass) one or more organisms to produce the hydroxyl-carboxylicacid. For example, the sugars can be fermented by a sugar fermentingorganism to the hydroxyl acid. Sugars that are released from the biomasscan be purified (e.g., prior to fermenting) by, for example, a methodselected from electrodialysis, distillation, centrifugation, filtration,cation exchange chromatography and combinations of these in any order.

In some implementation, converting comprises polymerizing thehydroxyl-carboxylic acid to a polymer in successive steps of increasingconversion as measured by degree of polymerization. The degree ofpolymerization is based on the number average molecular weight, Mn. Thepolymerization can be in a melt (e.g., without a solvent and above themelting point of the polymer), can be in a solid state, or can be in asolution (e.g., with an added solvent).

Optionally, when the polymerization method is direct condensation, thepolymerization can include utilizing coupling agents and/or chainextenders to increase the molecular weight of the polymer. For example,the coupling agents and/or chain extenders can include triphosgene,carbonyl diimidazole, dicyclohexylcarbodiimide, diisocyanate, acidchlorides, acid anhydrides, epoxides, thiirane, oxazoline, orthoester,and mixtures of these. Alternatively, the polymer can have a co monomerwhich is a polycarboxylic acid or polyols or a combination of these.

Optionally, polymerizations can be done utilizing catalysts and/orpromoters. The catalyst can be added after a desired degree ofpolymerization is obtained. For example, protonic acids and Lewis acidsmay be used. Examples of the acids include sulfonic acids, H₃PO₄, H₂SO₄,sulfonic acids, e, g, methane sulfonic acid, p-toluene sulfonic acid,Nafion® NR 50 H⁺ form From DuPont, Wilmington Del. (sulfonic acidsupported/bonded to a polymer that optionally may have atetrafluorethylene backbone), acids supported on or bonded ontopolymers, metals, Mg, Al, Ti, Zn, Sn, metal oxides, TiO₂, ZnO, GeO₂,ZrO₂, SnO, SnO₂, Sb₂O₃, metal halides, ZnCl₂, SnCl₂, AlCl₃ SnCl₄,Mn(AcO)₂, Fe₂(LA)₃, Co(AcO)₂, Ni(AcO)₂, Cu(OA)₂, Zn(LA)₂, Y(OA)₃,Al(i-PrO)₃, Ti(BuO)₄, TiO(acac)₂, (Bu)₂SnO, tin octoate, solvates of anyof these and mixtures of these can be used. For instance, p-toluenesulfonic acid and tin octoate or tin chloride may be used together.

The polymerizations can be done at a temperature between about 100 andabout 260° C., such as between about 110 and about 240° C. or betweenabout 120 and about 200° C. Optionally, at least a portion of thepolymerizations can be performed under vacuum (e.g., between about 0.005to 300 kPa).

After the polymerization has reached the desired molecular weight, itmay be necessary to deactivate and/or remove the catalyst from thepolymer. The catalyst can be reacted with a variety of compounds,including, silica, functionalized silica, alumina, clays, functionalizedclays, amines, carboxylic acids, phosphites, acetic anhydride,functionalized polymers, EDTA and similar chelating agents.

While not being bound by theory for those catalysts like the tinsystems, if the added compound can occupy multiple sites on the tin itcan be rendered inactive for polymerization (and depolymerization). Forexample, a compound like EDTA can occupy several sites in thecoordination sphere of the tin and, in turn, interfere with thecatalytic sites in the coordination sphere. Alternatively, the addedcompound can be of sufficient size and the catalyst can adhere to itssurface, such that the absorbed catalyst may be filtered from thepolymer. Those added compounds such as silica may have sufficientacidic/basic properties that the silica adsorbs the catalyst and isfilterable.

In the implementations wherein polymers are made from the D-lactic acidand/or L-lactic acid or other hydroxy-carboxylic acids, the methods canfurther include blending the polymer with a second polymer. For example,a second polymer can include polyglycols, polyvinyl acetate,polyolefins, styrenic resins, polyacetals, poly(meth)acrylates,polycarbonate, polybutylene succinate, elastomers, polyurethanes,natural rubber, polybutadiene, neoprene, silicone, and combinations ofthese. This blending is intended to create a physical blend of polymers.The blending may be accomplished in the thin filmpolymerization/devolatilization device by adding the second polymer intothe recycle loop or utilizing the optional extruder. After the blendingis complete, crosslinking means may be done to crosslink the polymerswith crosslinking additives or crosslinking processes described below.Peroxides may be added to facilitate crosslinking.

In other implementations wherein polymers are made from thehydroxy-carboxylic acid a co-monomer can be co-polymerized with thehydroxy-carboxylic acid. For example, the co-monomer can includeelastomeric units, lactones, glycolic acid, carbonates,morpholinediones, epoxides, 1,4-benzodioxepin-2,5-(3H)-dioneglycosalicylide, 1,4-benzodioxepin-2,5-(3H, 3-methyl)-dionelactosalicylide, dibenzo-1,5 dioxacin-6-12-dione disalicylide,morpholine-2,5-dione, 1,4-dioxane-2,5-dione glycolide, oxepane-2-oneε-caprolactone, 1,3-dioxane-2-one trimethylene carconate,2,2-dimethyltrimethylene carbonate, 1,5-dioxepane-2-one,1,4-dioxane-2-one p-dioxanone, gamma-butyrolactone, beta-butyrolactone,beta-me-delta-valerolactone, 1,4-dioxane-2,3-dione ethylene oxalate,3-[benzyloxycarbonylmethyl]-1,4-dioxane-2,5-dione, ethylene oxide,propylene oxide, 5,5′(oxepane-2-one),2,4,7,9-tetraoxa-spiro[5,5]undecane-3,8-dione Spiro-bid-dimethylenecaronate and mixtures of these.

The polymers of poly hydroxy-carboxylic acids are polyesters. Thesepolymers may be modified by adding or aromatic alcohols and/or oraromatic carboxylic acids during one of the steps in the polymerizationprocess. An optional place to add these alcohols and/or carboxylic acidsare at the processing by the thin film polymerization/devolatilizationdevice. An optional combination of alcohols and carboxylic acids, are toadd nearly equimolar amounts of diols and dicarboxylic acids to the polyhydroxy-carboxylic acids. By holding the ratio of diols to dicarboxylicacids nearly equimolar the resultant higher molecular weight polymerwill have properties similar to the parent poly hydroxy-carboxylicacids, but with the advantages of the higher molecular weight of thepolymer. Optionally, the ratio of aliphatic or aromatic diols and/oraliphatic or aromatic carboxylic diacids is from 0.95 to 1.05; or 0.975to 1.025.

Tri substituted polyols and/or trisubstituted carboxylic acids may alsobe added to the poly hydroxy-carboxylic acid to obtain a crosslinkedmaterial. The mole ratio of these trisubstituted additives must be lessthan 10 mole percent, optionally, less than 5 mole percent, or furtheroptionally, less than 2 mole percent based on the total number ofmonomer units of the poly hydroxy-carboxylic acids. These trisubstituted can be processed/added to the polymer melt in the thin filmpolymerization/devolatilization device or can be processed/added to thepolymer melt in the extruder.

The diol and dicarboxylic acids and the triol and/or trisubstitutedcarboxylic acids may be added at any of the steps c, e and f describedabove.

In general, to achieve high molecular weights of the polyhydroxy-carboxylic acid the total moles of alcohol groups and carboxylicacid groups should be controlled close to equimolar amounts of alcoholand carboxylic acid groups. The difference from equimolar should be morethan 0.90 to no more than 1.10 mole ratio of alcohol to carboxylic acid.Additionally, the ratio is more than 0.95 to no more than 1.05 and,optionally, more than 0.98 to no more than 1.02. The calculation ofalcohol and carboxylic acid should include any di and tri substitutedcompounds described above.

When the di and/or trisubstituted reactants are included in thepolymerization steps 1, 2 and 3 or especially steps 2 and 3, theresultant polymer can be a block polymer with blocks of the polyhydroxy-carboxylic acids units separated by the added di and/ortrisubstituted monomers.

The diol/triol and diacid/triacid additives can be controlled based onthe monomer units of the poly hydroxy-carboxylic acid. In oneembodiment, the total moles of the diol/triol and diacid/triacidadditives can be less than 10 mole percent of the monomer units of thepoly hydroxy-carboxylic acids. For instance, for the monomer D-lacticacid and/or L-lactic acid the Mn molecular weight is divided by 72 todetermine the number if monomer units. The 72 is obtained from the 90molecular weight of D-lactic acid and/or L-lactic acid less that water(molecular weight 18) which is a byproduct of each condensation step.

In any implementation wherein polymers are made, the method can furtherinclude branching and/or cross linking the polymer. For example, thepolymers can be treated with a cross linking agent including5,5′-bis(oxepane-2-one)(bis-ε-caprolactone)), spiro-bis-dimethylenecarbonate, peroxides, dicumyl peroxide, benzoyl peroxide, unsaturatedalcohols, hydroxyethyl methacrylate, 2-butene-1,4-diol, unsaturatedanhydrides, maleic anhydride, saturated epoxides, glycidyl methacrylate,irradiation and combinations of these. Optionally, a molecule (e.g., apolymer) can be grafted to the polymer. For example, grafting can bedone treating the polymer with irradiation, peroxide, crossing agents,oxidants, heating or any method that can generate a cation, anion, orradical on the polymer.

In any implementation wherein polymers are processed, processing caninclude injection molding, blow molding, spinning into fibers andthermoforming.

In any implementation wherein polymers are made, the polymers can becombined with fillers (e.g., by extrusion and/or compression molding).For example, some fillers that can be used include silicates, layeredsilicates, polymer and organically modified layered silicate, syntheticmica, carbon, carbon fibers, glass fibers, boric acid, talc,montmorillonite, clay, starch, corn starch, wheat starch, cellulosefibers, paper, rayon, non-woven fibers, wood flours, whiskers ofpotassium titanate, whiskers of aluminum borate, 4,4′-thiodiphenol,glycerol and mixtures of these.

In any implementation wherein polymers are processed, the polymers canbe combined with a dye and/or a fragrance. For example, dyes that can beused include blue3, blue 356, brown 1, orange 29, violet 26, violet 93,yellow 42, yellow 54, yellow 82 and combinations of these. Examples offragrances include wood, evergreen, redwood, peppermint, cherry,strawberry, peach, lime, spearmint, cinnamon, anise, basil, bergamot,black pepper, camphor, chamomile, citronella, eucalyptus, pine, fir,geranium, ginger, grapefruit, jasmine, juniper berry, lavender, lemon,mandarin, marjoram, musk, myrrh, orange, patchouli, rose, rosemary,sage, sandalwood, tea tree, thyme, wintergreen, ylang ylang, vanilla,new car or mixtures of these fragrances. Fragrances can be used in anyamount, for example, between about 0.005% by weight and about 20% byweight (e.g., between about 0.1% and about 5 wt. %, between about 0.25wt. % and about 2.5%).

In any implementation wherein polymers are processed, the polymer can beblended with a plasticizer. For example, plasticizers include triacetin,tributyl citrate, polyethylene glycol, GRINDSTED® SOFT-N-SAFE (fromDanisco, DuPont, Wilmington Del., diethyl bishydroxymethyl malonate andmixtures of these.

In any of the implementations wherein polymers are made, the polymerscan be processed or further processed by shaping, molding, carving,extruding and/or assembling the polymer into the product.

In another aspect, the disclosure relates to products made by themethods discussed above. For example, the products include a convertedhydroxyl-carboxylic acid wherein the hydroxyl-carboxylic acid isproduced by the fermentation of biomass derived sugars (e.g., glycolicacid, D-lactic acid and/or L-lactic acid, D-malic acid, L-malic, citricacid and D-tartaric acid, L-tartaric acid and meso-tartaric acid). Thebiomass includes cellulosic and lignocellulosic materials and these canrelease sugars by acidic or enzymatic saccharification. In addition, thebiomass can be treated, e.g., by irradiation.

The products, for example, include polymers, including one or morehydroxyl acids in the polymer backbone and optionallynon-hydroxyl-carboxylic acid s in the polymer backbone. Optionally thepolymers can be cross-linked or graft co-polymers. Optionally thepolymer can be, blended with a second polymer, blended with aplasticizer, blended with an elastomer, blended with a fragrance,blended with a dye, blended with a pigment, blended with a filler orblended with a combination of these.

Some of the products described herein, for example, D-lactic acid and/orL-lactic acid, can be produced by chemical methods. However,fermentative methods can be much more efficient, providing high biomassconversion, selective conversion and high production rates. Inparticular, fermentative methods can produce D or L isomers ofhydroxyl-carboxylic acid s (e.g., lactic acid) at chiral purity of near100% or mixtures of these isomers, whereas the chemical methodstypically produce racemic mixtures of the D and L isomers. When ahydroxy-carboxylic acid is listed without its stereochemistry it isunderstood that D, L, meso, and/or mixtures are assumed.

The methods describe herein are also advantageous in that the startingmaterials (e.g., sugars) can be completely derived from biomass (e.g.,cellulosic and lignocellulosic materials). In addition, some of theproducts described herein such as polymers of hydroxyl-carboxylic acid s(e.g., poly lactic acid) are compostable, biodegradable and/orrecyclable. Therefore, the methods described herein can provide usefulmaterials and products from renewable sources (e.g., biomass) whereinthe products themselves can be re-utilized or simply safely returned tothe environment.

For example, some products that can be made by the methods, systems orequipment described herein include personal care items, tissues, towels,diapers, green packaging, compostable pots, consumer electronics, laptopcasings, mobile phone casings, appliances, food packaging, disposablepackaging, food containers, drink bottles, garbage bags, wastecompostable bags, mulch films, controlled release matrices, controlledrelease containers, containers for fertilizers, containers forpesticides, containers for herbicides, containers for nutrients,containers for pharmaceuticals, containers for flavoring agents,containers for foods, shopping bags, general purpose film, high heatfilm, heat seal layer, surface coating, disposable tableware, plates,cups, forks, knives, spoons, sporks, bowls, automotive parts, panels,fabrics, under hood covers, carpet fibers, clothing fibers, fibers forgarments, fibers for sportswear, fibers for footwear, surgical sutures,implants, scaffolding and drug delivery systems.

Other features and advantages of the disclosure will be apparent fromthe following detailed description, and from the claims.

DESCRIPTION OF THE DRAWING

The foregoing will be apparent from the following more particulardescription of example embodiments of the disclosure, as illustrated inthe accompanying. The drawings are not necessarily to scale, emphasisinstead being placed upon illustrating embodiments of the presentdisclosure.

FIG. 1 shows a generalized scheme for the polymerization process withthe thin film polymerization/devolatilization device.

FIG. 2 a shows a schematic of a polymerization unit that has an exampleof a thin film polymerization/devolatilization device and an extruder.

FIG. 2 b shows a cutaway of the thin filmpolymerization/devolatilization device with the sloped surface uponwhich the molten polymer flows.

FIG. 3 is a flow diagram showing processes for manufacturing productsfrom a biomass feedstock.

FIG. 4 is a schematic showing some possible chemical pathways forproducing poly lactic acid.

FIG. 5 is a plot of lactic acid production in a 1.2 L Bioreactor.

FIG. 6 is a plot of lactic acid production in a 20 L Bioreactor.

FIG. 7 is a plot of GPC data for poly lactic acid.

FIG. 8 shows the chemical structures of some exemplary hydroxyl acids.

FIG. 9 a shows a small scale polymerization unit that has an example ofa laboratory-scale thin film polymerization/devolatilization device.

FIG. 9 b shows a cutaway of the thin filmpolymerization/devolatilization device with the sloped surface uponwhich the molten polymer flows.

FIG. 10 shows a schematic of a shell and tube heat exchanger with moltenflow of polymer down the inside surface of the tubes.

DETAILED DESCRIPTION

Using the equipment, methods and systems described herein, cellulosicand lignocellulosic feedstock materials, for example, that can besourced from biomass (e.g., plant biomass, animal biomass, paper, andmunicipal waste biomass) and that are often readily available butdifficult to process, can be turned into useful products such as sugarsand hydroxy-carboxylic acids. Included are equipment, methods andsystems to chemically convert the hydroxy-carboxylic acids productsproduced from the biomass to a secondary product such as polymers (e.g.,poly hydroxy-carboxylic acid) and polymer derivatives (e.g., composites,elastomers and co-polymers).

Hydroxy-carboxylic acids can undergo condensation reactions to obtainpolyester polymers. Since the hydroxy-carboxylic acids and the polymericproducts are derived from biomass they are a renewable product.

In one embodiment, the method of making a high molecular weight polymeror copolymer from oligomer, the method comprising evaporating water asit is formed during condensation of an hydroxy-carboxylic acid oligomere.g. an aliphatic hydroxy carboxylic acid, as it traverses a surface ofa thin film evaporator. Water, as a coproduct of the condensation, needsto be removed from the high molecular weight polymer or copolymer, tomaximize the conversion to higher molecular weight materials andminimize the undesirable reverse reaction where the water adds back andreleases a monomer unit, dimer unit or oligomer of thehydroxyl-carboxylic acid.

In another embodiment, the thin film evaporator unit operation isdescribed in more detail and the polymerization process is denoted inthree steps or stages for the conversion to high molecular weightpolymers. FIG. 1 shows a schematic of the polymerization process withthe three polymerization steps indicated. A recycle loop which takes theproduct of the thin film evaporator/thin filmpolymerization/devolatilization device and recycle to the input of thethin film evaporator/thin film polymerization/devolatilization device.The thin film evaporator/thin film polymerization/devolatilizationdevice product stream may be split between recycle and sending a portionof the product stream to product collection.

First, excess water is removed from the hydroxyl-carboxylic acid. As theacid is derived from biomass processing, it is likely in an aqueoussolvent. The condensation process to make the polyester produces waterand thus, the excess water must be removed. The removal may be done in abatch or continuous process, with or without vacuum and at temperaturesto achieve effective water removal rates. Some condensation to formester bonds can occur during step 1 and low molecular weight oligomersmay be formed.

After excess water is removed, further heating and, optional processingwith vacuum to remove more water. At this stage in the process, theconversion of the hydroxy-carboxylic acid results in a degree ofoligomerization is about 5 to about 50 based on the number averagemolecular weight of the oligomer/polymer.

A polymerization catalyst is added to the oligomer/polymer system. Thecandidate polymer catalyst(s) is described above and further describedbelow. The catalyst may be added by any convenient means. For instance,the catalyst components can be dissolved/dispersed into thehydroxy-carboxylic acid and added to the oligomer/polymer with degree ofoligomerization of about 5 to 50.

With the catalyst present more conversion of the oligomer/polymermixture occurs to obtain a degree of polymerization of about 35 to about500. This is achieved by the catalytic action of the catalysts added anda combination of more heating and higher vacuums.

Next the thin film polymerization/devolatilization device is utilized toobtain polymers with a degree of polymerization of about 300 to about20,000. The thin film has a thickness of less than 1 cm, optionally lessthan 0.5 cm, or further less than 0.25 cm, additional less than 0.1 cm.

Throughout the process and when the catalyst is added cyclic dimersderived from the hydroxy-carboxylic acid are less than 10 weight percentbased on the total mass of the hydroxy-carboxylic acids monomers,oligomers and polymers (and copolymers). The thin filmpolymerization/devolatilization device is configured such that fluidpolymer is conveyed to the device such that the film of the fluidpolymer is less than 1 cm thick and the device provides a means forvolatilizing the water formed in the reaction and other volatilecomponents. The polymerization type is characterized as polymerizationin the melt phase. The thin/film polymerization/devolatilization deviceand the thin film evaporator describe herein are similar in that theyaccomplish the same function. When the hydroxy-carboxylic acid isD-lactic acid and/or L-lactic acid, the cyclic dimer is denoted aslactide, although lactide can more generally refer these cyclic dimers.For lactic acid, the lactide is 3,6-dimethyl-1,4-dioxane-2,5-dione, withno stereochemistry denoted.

Optionally, the hydroxy-carboxylic cyclic dimers are less than 5 weightpercent based on the total mass of the hydroxy-carboxylic monomers,oligomers and polymers (copolymers). In another embodiment, thehydroxy-carboxylic cyclic dimers are less than 2.5 based on the totalmass of the hydroxy-carboxylic acids monomers, oligomers and polymersweight percent.

The hydroxylic medium can be water; mixtures of water and compatiblesolvents such as methanol, ethanol; and low molecular weight alcoholssuch as methanol, ethanol, n-propanol, iso-propanol, n-butanol,iso-butanol, and similar alcohols.

The temperature of the thin film polymerization/devolatilization deviceis from 100 to 260° C. Optionally, the temperature of the thin filmpolymerization/devolatilization device is from 120 to 240° C.Additionally, the temperature is between 140 and 220° C.

The thin film polymerization/devolatilization device can operate at highvacuum with pressures of 0.0001 torr and lower. The thin filmpolymerization/devolatilization device can operate e.g. at 0.001 torr orlower; or 0.01 torr or lower. During some stages of operation theoperating pressures can be considered low and medium vacuum; 760 to 25torr and 25 to 0.001 torr, respectively. The device may operate at apressure of 100 to 0.0001 torr, or alternatively, 50 to 0.001 torr, oroptionally, 25 to 0.001 torr.

The thin film polymerization/devolatilization device can optionallyinclude a recycle loop in which the melt polymerization product isrecycled to the entrance point of the thin filmpolymerization/devolatilization device. It can also be coupled to anextrusion device. The melt polymerization product can be processed fromthe thin film polymerization/devolatilization device to an extruderwhich can pass the product to finished product area. Alternately, theflow of the output of the extruder may be directed back to the thin filmpolymerization/devolatilization device. The flow may be split betweenthe product and the recycle. The extruder system is a convenientlocation to incorporate additives into the melt polymerization productfor recycle and subsequent reaction or for blending into the polymerstream prior to transferring to the product finishing area. Theadditives were described above and below. The additive addition includescompounds that react into the polymer, react on the polymer orphysically mix with the polymer.

FIG. 2 a is a schematic of a polymerization system to polymerize hydroxycarboxylic acid. The thin film evaporator or thin filmpolymerization/devolatilization device (200), an (optional) extruder(202) for product isolation or recycle back to the thin film evaporatoror thin film polymerization/devolatilization device, a heated recycleloop (204), a heated condenser (206), cooled condenser (208) forcondensing water and other volatile components, a collection vessel(210) a fluid transfer unit (212) to remove condensed water and volatilecomponents {this effluent may be taken to a another unit operation torecover the useful volatile components for recycle back to Step 1}, anda product isolation device (214). The thin film evaporator or thin filmpolymerization/devolatilization device comprises Step 3 in the processdescription discussed above. The fluid transfer unit is shown as a pump.

FIG. 2 is a cutaway of the thin film polymerization/devolatilizationdevice. The angled rectangular piece (250) is the optionally heatedsurface where the molten polymer flows. The incoming molten polymerstream (252) flows onto the surface and is shown as an ellipse (258) offlowing polymer flowing to the exit of the device at (254). Thevolatiles are removed at (256).

The internals of the thin film evaporator or thin filmpolymerization/devolatilization device can be in differentconfigurations, but must be configured to assure that the polymer fluidflows in a thin film through the device. This is to facilitatevolatilization of the water that is in the polymer fluid or is formed bya condensation reaction. For instance, the surface may be slanted at anangle relative to the straight sides of the device. The surface may beseparately heated such that the surface is 0 to 40° C. hotter than thepolymer fluid. With this heated surface it can be heated to up to 300°C., as much as 40° C. higher than the overall temperature of the device.

The thickness of the polymer fluid flowing along the thin film part ofthe device is less than 1 cm, optionally less than 0.5 cm or alternatelyless than 0.25 cm.

The thin film evaporator and thin film polymerization/devolatilizationdevice are similar in function. Other similar devices similar infunction should be considered to have the same function as these.Descriptively, these include wiped film evaporators, short pathevaporator, a shell and tube heat exchanger and the like. For each ofthese evaporator configuration a distributor may be used to assuredistribution of the thin film. The limitation that they must be able tooperate at the conditions described above.

Optionally, the catalyst may be removed from the molten polymer.Removing catalyst may be accomplished just prior to, during, or afterthe thin film evaporator/thin film polymerization/devolatilizationdevice. The catalyst may be filtered from the molten polymer by using afiltration system similar to a screen pack. Since the molten polymer isflowing around the thin film evaporator/thin filmpolymerization/devolatilization device, a filtration system can beadded.

To facilitate the catalyst removal a neutralization or chelationchemical may be added. Candidate compounds include phosphites,anhydrides, poly carboxylic acids, polyamines, hydrazides, EDTA (andsimilar compounds) and the like. These neutralization and/or chelationcompounds can be insoluble in the molten polymer leading to facilefiltration. Poly carboxylic acids include poly acrylic acids and polymethacrylic acids. The latter can be in a both a random, block, andgraft polymer configuration. The amines include ethylene diamine,oligomers of ethylene diamine and other similar polyamines such asmethyl bis-3-amino, propane.

Another option to remove the catalyst includes adding solid materials tothe polymer melt. Examples of added materials include silica, alumina,aluminosilicates, clays, diatomaceous earth, polymers and like solidmaterials . Each of these can be optionally functionalized to react/bindwith the catalyst. When the catalyst binds/bonds to these structures itcan be filtered from the polymer.

The (co)polymer product is isolated when the desired conversion/physicalproperties are achieved. The product can be conveyed to a productcollection /isolation area. Optionally, a final devolatilization stepmay be performed just prior to product isolation. Types of equipment toisolate the (co)polymer product can include rotoform pastillation systemand similar systems in which the product is cooled to obtain a productin a useable form.

Assessment when the product can be sent to product isolation can includetaking samples and measuring important parameters such as molecularweight and polydispersity. Optionally, a continuous measurement can beused such as including an in-line viscometer which can measure intrinsicviscosity.

The thin film evaporator and thin film polymerization/devolatilizationdevice can be made of any normally used metals for chemical processingequipment. Since the hydroxy-carboxylic acids can be corrosive the thinfilm evaporator may be clad or coated with corrosive resistant metalssuch as tantalum, alloys such as Hastelloy™, a trademarked alloy fromHaynes International, and the like. It can also be coated with inerthigh temperature polymeric coatings such as Teflon™ from DuPont,Wilmington Del. The corrosivity of the hydroxy-carboxylic acid systemmay not be surprising since the pKa of lactic acid is more than 0.8 lessthan acetic acid. Also, water undoubtedly hydrates the acid and the acidend of the polymer. When those waters of hydration are removed theacidity can be much higher, since it is not leveled by the waters ofhydration.

FIG. 9 a is a schematic of a pilot-scale polymerization system topolymerize hydroxy carboxylic acid. The thin film evaporator or thinfilm polymerization/devolatilization device (900), a heated riser (902),a cooled condenser (904) for condensing water and other volatilecomponents, a collection vessel (906) a fluid transfer unit (908) torecycle the polymer fluid shown as a pump. The connecting tubing is notshown for clarity. The output of the pump (916) is connected to inlet(910), the device output (912) is connected to the inlet of the pump(914). The product isolation section is not shown. Internal in the thinfilm polymerization/devolatilization device is a slanted surface. Thepolymer fluid is flowed to the inlet with the configured such that thepolymer fluid flows onto the slanted surface. This slanted surface maybe separately heated as described above.

FIG. 9 b is a cutaway of the thin film polymerization/devolatilizationdevice. The angled rectangular piece (950) is the optionally heatedsurface where the molten polymer flows. The incoming molten polymerstream (952) flows onto the surface and is shown as a trapezoid (956) offlowing polymer flowing to the exit of the device at (954).

An alternate thin film evaporator/devolatilization can be a shell andtube heat exchanger. A schematic is shown in FIG. 10. The shell (1002)and tube (1008) with only one of the tubes labeled. The molten polymerflow (1006) is depicted is entering the left side of each tube, butcould also a distributor could be present that would distribute thepolymer flow to the inside surface of the tubes to assure the thin filmthickness of less than 1 cm is obtained. The collection of the polymerflow is at 1004.

To facilitate removal of water a stripping gas may be included in thesystem especially toward the exit of the thin film evaporator or thinfilm polymerization devolatilization device. The capacity of the vacuummust accommodate the use of stripping gas.

Additives can be added just prior, during or after the thin filmevaporator or thin film polymerization/devolatilization device. Theseadditives can include but are not limited to polymers for blending,reactive polymers, reactive monomers, other condensation monomers,catalyst stabilization agents, anti-oxidants peroxides for crosslinkingpolymer chains. These additives are more fully described below.

Biomass Processing to Produce Hydroxy-Carboxylic Acids

The hydroxy-carboxylic acid is prepared from biomass. For example,lignocellulosic materials include different combinations of cellulose,hemicellulose and lignin. Cellulose is a linear polymer of glucose.Hemicellulose is any of several heteropolymers, such as xylan,glucuronoxylan, arabinoxylans and xyloglucan. The primary sugar monomerpresent (e.g., present in the largest concentration) in hemicellulose isxylose, although other monomers such as mannose, galactose, rhamnose,arabinose and glucose are present. Although all lignins show variationin their composition, they have been described as an amorphous dendriticnetwork polymer of phenyl propene units. The amounts of cellulose,hemicellulose and lignin in a specific biomass material depend on thesource of the biomass material. For example, wood-derived biomass can beabout 38-49% cellulose, 7-26% hemicellulose and 23-34% lignin dependingon the type. Grasses typically are 33-38% cellulose, 24-32%hemicellulose and 17-22% lignin. Clearly lignocellulosic biomassconstitutes a large class of substrates.

Enzymes and biomass-destroying organisms that break down biomass, suchas the cellulose, hemicellulose and/or the lignin portions of thebiomass as described above, contain or manufacture various cellulolyticenzymes (cellulases), ligninases, xylanases, hemicellulases or varioussmall molecule biomass-destroying metabolites. A cellulosic substrate isinitially hydrolyzed by endoglucanases at random locations producingoligomeric intermediates. These intermediates are then substrates forexo-splitting glucanases such as cellobiohydrolase to produce cellobiosefrom the ends of the cellulose polymer. Cellobiose is a water-soluble1,4-linked dimer of glucose. Finally, cellobiase cleaves cellobiose toyield glucose. In the case of hemicellulose, a xylanase (e.g.,hemicellulase) acts on this biopolymer and releases xylose as one of thepossible products.

FIG. 3 is a flow diagram showing processes for manufacturing is a flowdiagram showing processes for manufacturing hydroxyl-carboxylic acid sfrom a feedstock (e.g., cellulosic or lignocellulosic materials). In aninitial step (310) the method includes optionally mechanically treatinga cellulosic and/or lignocellulosic feedstock, for example, tocomminute/size reduce the feedstock. Before and/or after this treatment,the feedstock can be treated with another physical treatment (312), forexample, irradiation, heat treatment, sonication, steam explosion,oxidation, pyrolysis or combinations of these, to reduce or furtherreduce its recalcitrance. A sugar solution e.g., including glucoseand/or xylose, is formed by saccharifying the feedstock (314). Thesaccharification can be, for example, accomplished efficiently by theaddition of one or more enzymes, e.g., cellulases and/or xylanases (311)and/or one or more acids. A product or several products can be derivedfrom the sugar solution, for example, by fermentation to ahydroxyl-carboxylic acid (316). Following fermentation, the fermentationproduct (e.g., or products, or a subset of the fermentation products)can be purified or they can be further processed, for example,polymerized and/or isolated (324). Optionally, the sugar solution is amixture of sugars and the organism selectively ferments only one of thesugars. The fermentation of only one of the sugars in a mixture can beadvantageous as described in International App. No. PCT/US2014/021813filed Mar. 7, 2014, the entire disclosure of which is incorporatedherein by reference. If desired, the steps of measuring lignin content(318) and setting or adjusting process parameters based on thismeasurement (320) can be performed at various stages of the process, forexample, as described in U.S. Pat. No. 8,415,122, issued Apr. 9, 2013the entire disclosure of which is incorporated herein by reference.Optionally, enzymes (e.g., in addition to cellulases and xylanases) canbe added in step (114), for example, a glucose isomerase can be used toisomerize glucose to fructose. Some relevant uses of isomerase arediscussed in International Application No. PCT/US12/71093, filed on Dec.20, 2012, published as WO 2013/096700 the entire disclosure of which isincorporated herein by reference.

In some embodiments the liquids after saccharification and/orfermentation can be treated to remove solids, for example, bycentrifugation, filtration, screening, or rotary vacuum filtration. Forexample, some methods and equipment that can be used during or aftersaccharification are disclosed in U.S. application Ser. No. 13/932,814filed on Jul. 1, 2013, published as US 2014/0004573; and InternationalApp. No. PCT/US2014/021584, filed on Mar. 7, 2014, the entiredisclosures of which are incorporated herein by reference. In additionother separation techniques can be used on the liquids, for example, toremove ions and de-colorize. For example, chromatography, simulatedmoving bed chromatograph and electrodialysis can be used to purify anyof the solutions and or suspensions described herein. Some of thesemethods are discussed in International App. No. PCT/US2014/021638, filedon Mar. 7, 2014, and International App. No. PCT/US2014/021815, filed onMar. 7, 2014, the entire disclosures of which are incorporated herein byreference. Solids that are removed during the processing can be utilizedfor energy co-generation, for example, as discussed in InternationalApp. No. PCT/US2014/021634, filed on Mar. 7, 2014, the entire disclosureof which is herein incorporated by reference. Optionally, the sugarsreleased from biomass as describe in FIG. 3, for example, glucose,xylose, sucrose, maltose, lactose, mannose, galactose, arabinose,homodimers and heterodimers of these (e.g., cellobiose, sucrose),trimers, oligomers and mixtures of these, can be fermented tohydroxyl-carboxylic acid s such as alpha, beta or gamma hydroxyl acids(e.g., lactic acid). In some embodiments the saccharification andfermentation are done simultaneously, for example, using thethermophilic organism such as Baccillus coagulans MXL-9 as described byS. L. Walton in J. Ind. Microbiol. Biotechnol. (2012) pg. 823-830.

Hydroxy-carboxylic acids that can be produced by the methods, systems,and equipment described herein include, for example, of alpha, beta,gamma and delta hydroxy-carboxylic acids. FIG. 8 shows the chemicalstructures of some hydroxyl acids. That is, if there is only onehydroxyl group it can be at any of the alpha, beta, gamma or deltacarbon atoms in the carbon chain. The carbon chain may be a straightchain, branched or cyclic system. The hydroxy carboxylic acid may alsoinclude fatty acids of carbon chain lengths of 10 to 22 with the hydroxysubstituent at the alpha, beta, gamma, or delta carbon.

The hydroxy-carboxylic acids include those with multiple hydroxysubstituents, or in alternative description a poly hydroxy substitutedcarboxylic acid. Such hydroxy-carboxylic acids can bepoly-hydroxy-carboxylic acid, e.g. di-, tri-, tetra-, penta-, hexa-hepta- and octa-hydroxy substituted carboxylic acid. The carbon chain ofthe carboxylic acid may be straight chained, branched, cyclic, oralicyclic. Examples of this are tartaric acid and its isomers,dihydroxy-3-methylpentanoic acid, 3,4-dihydroxymandelic acid, gluconicacid, glucuronic acid and the like.

For example, glycolic acid, lactic acid (e.g., D, L or mixtures of D andL), malic acid (e.g., D, L or mixtures of D and L), citric acid,tartaric acid (e.g., D, L or mixtures of D and L), carmine,cyclobutyrol, 3-dehydroquinic acid, diethyl tartrate,2,3-dihydroxy-3-methylpentanoic acid, 3,4-dihydroxymandelic acid,glyceric acid, homocitric acid, homoisocitric acid, beta-hydroxybeta-methylbutyric acid, 4-hydroxy-4-methylpentanoic acid,hydroxybutyric acid, 2-hydroxybutyric acid, beta-hydroxybutyric acid,gamma-hydroxybutyric acid, alpha-hydroxyglutaric acid,5-hydroxyindoleacetic acid, 3-hydroxyisobutyric acid, 3-hydroxypentanoicacid, 3-hydroxypropionic acid, hydroxypyruvic acid, gamma-hydroxyvalericacid, isocitric acid, isopropylmalic acid, kynurenic acid, mandelicacid, mevalonic acid, monatin, myriocin, pamoic acid, pantoic acid,prephenic acid, shikimic acid, tartronic acid, threonic acid, tropicacid, vanillylmandelic acid, xanthurenic acid and mixtures of these. Forthose hydroxyl acids listed all of the stereo isomers are included inthe list. For instance, tartaric acid includes, the D, L, and mesoisomers and mixtures thereof.

Preparation of Hydroxy-Carboxylic Acid

Organisms can utilize a variety of metabolic pathways to convert thesugars to hydroxy-carboxylic acid, and some organisms selectively onlycan use specific pathways. A well-studied example is lactic acid. Someorganisms are homofermentative while others are heterofermentative. Forexample, some pathways are described in Journal of Biotechnology 156(2011) 286-301. The pathway typically utilized by organisms fermentingglucose is the glycolytic pathway. Five carbon sugars, such as xylose,can utilize the heterofermentative phosphoketolase (PK) pathway. The PKpathway converts two of the 5 carbons in xylose to acetic acid on theremaining 3 to lactic acid (through pyruvate). Another possible pathwayfor five carbon sugars is the pentose phosphate (PP)/glycolytic pathwaythat only produces lactic acid.

Several organisms can be utilized to ferment the biomass derived sugarsto lactic acid. The organisms can be, for example, lactic acid bacteriaand fungi. Some specific examples include Rhizopus arrhizus, Rhizopusoryzae, (e.g., NRRL-395, ATCC 52311, NRRL 395, CBS 147.22, CBS 128.08,CBS 539.80, CBS 328.47, CBS 127.08, CBS 321.35, CBS 396.95, CBS 112.07,CBS 127.08, CBS 264.28), Enterococcus faecalis (e.g. RKY1),Lactobacillus rhamnosus (e.g. ATCC 10863. ATCC 7469, CECT-288, NRRLB-445), Lactobacillus helveticus (e.g. ATCC 15009, R211), Lactobacillusbulgaricus (e.g. NRRL B-548, ATCC 8001, PTCC 1332), Lactobacillus casei(e.g. NRRL B-441), Lactobacillus plantarum (e.g. ATCC 21028, TISTR No.543, NCIMB 8826), Lactobacillus pentosus (e.g. ATCC 8041), Lactobacillusamylophilus (e.g. GV6), Lactobacillus delbrueckii (e.g. NCIMB 8130,TISTR No. 326, Uc-3, NRRL-B445, IFO 3202, ATCC 9649), Lactococcus lactisssp. lactis (e.g. IFO 12007), Lactobacillus paracasei No. 8,Lactobacillus amylovorus (ATCC 33620), Lactobacillus sp. (e.g. RKY2),Lactobacillus coryniformis ssp. torquens (e.g. ATCC 25600, B-4390),Rhizopus sp. (e.g. MK-96-1196), Enterococcus casseliflavus, Lactococcuslactis (TISTR No. 1401), Lactobacillus casei (TISTR No. 390),Lactobacillus thermophiles, Bacillus coagulans (e.g., MXL-9, 36D1,P4-102B), Enterococcus mundtii (e.g., QU 25), Lactobacillus delbrueckii,Acremonium cellulose, Lactobacillus bifermentans, Corynebacteriumglutamicum, L. acetotolerans, L. acidifarinae, L. acidipiscis, L.acidophilus, L. agilis, L. algidus, L. alimentarius, L. amylolyticus, L.amylophilus, L. amylotrophicus, L. amylovorus, L. animalis, L. antri, L.apodemi, L. aviarius, L. bifermentans, L. brevis (e.g., B-4527), L.buchneri, L. camelliae, L. casei, L. catenaformis, L. ceti, L.coleohominis, L. collinoides, L. composti, L. concavus, L. coryniformis,L. crispatus, L. crustorum, L. curvatus, L. delbrueckii subsp.Delbrieckii (e.g., NRRL B-763, ATCC 9649), L. delbrueckii subsp.bulgaricus, L. delbrueckii subsp. lactis (e.g., B-4525), L. dextrinicus,L. diolivorans, L. equi, L. equigenerosi, L. farraginis, L. farciminis,L. fermentum, L. fornicalis, L. fructivorans, L. frumenti, L.fuchuensis, L. gallinarum, L. gasseri, L. gastricus, L. ghanensis, L.graminis, L. hammesii, L. hamsteri, L. harbinensis, L. hayakitensis, L.helveticus, L. hilgardii, L. homohiochii, L. iners, L. ingluviei, L.intestinalis, L. jensenii, L. johnsonii, L. kalixensis, L.kefiranofaciens, L. kefiri, L. kimchii, L. kitasatonis, L. kunkeei, L.leichmannii, L. lindneri, L. malefermentans, L. mali, L. manihotivorans,L. mindensis, L. mucosae, L. murinus, L. nagelii, L. namurensis, L.nantensis, L. oligofermentans, L. oris, L. panis, L. pantheris, L.parabrevis, L. parabuchneri, L. paracollinoides, L. parafarraginis, L.parakefiri, L. paralimentarius, L. paraplantarum, L. pentosus, L.perolens, L. plantarum (e.g., ATCC 8014), L. pontis, L. psittaci, L.rennini, L. reuteri, L. rhamnosus, L. rimae, L. rogosae, L. rossiae, L.ruminis, L. saerimneri, L. sakei, L. salivarius, L. sanfranciscensis, L.satsumensis, L. secaliphilus, L. sharpeae, L. siliginis, L. spicheri, L.suebicus, L. thailandensis, L. ultunensis, L. vaccinostercus, L.vaginalis, L. versmoldensis, L. vini, L. vitulinus, L. zeae, L. zymae,and Pediococcus pentosaceus (ATCC 25745).

Alternatively, the microorganism used for converting sugars tohydroxy-carboxylic acids, including lactic acid, Lactobacillus casei,Lactobacillus rhamnosus, Lactobacillus delbrueckii subspeciesdelbrueckii, Lactobacillus plantarum, Lactobacillus coryniformissubspecies torquens, Lactobacillus pentosus, Lactobacillus brevis,Pediococcus pentosaceus, Rhizopus oryzae, Enterococcus faecalis,Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus casei,lactobacillus amylophilus and mixtures thereof.

Using the methods, equipment and systems described herein, either D or Lisomers of lactic acid at an optical purity of near 100% (e.g., at leastabout 80%, at least about 85%, at least about 90%, at least about 95%,at least about 99%) can be produced. Optionally mixtures of the isomerscan be produced in any ratio, for example, from 0% optical purity of anyisomer up to 100% optical purity of any isomer, for example, the speciesLactobacillus delbrueckii (NRRL-B445) is reported to produce a mixtureof D and L isomers, Lactobacillus rhamnosus (CECT-28) is reported toproduce the L isomer while Lactobacillus delbrueckii (IF 3202) isreported to produce the D isomer (Wang et al. in Bioresource Technology,June, 2010). As a further example, organisms that predominantly producethe L(+)-isomer are L. amylophilus, L. bavaricus, L. casei, L.maltaromicus and L. salivarius, while L. delbrueckii, L. jensenii and L.acidophilus produce the D(−)-isomer or mixtures of both.

Genetically modified organisms can also be utilized. For example,genetically modified organisms (e.g., lactobacillus, Escherichia coli)that are modified to express either L-Lactate dehydrogenase or D-lactatedehydrogenase to produce more L-Lactic acid or D-Lactic acidrespectively. In additions some yeasts and Escherichia coli have beengenetically modified to produce lactic acid from glucose and/or xylose.

Co-cultures of organisms, for example, chosen from organisms as describeherein, can be used in the fermentations of sugars to hydroxy-carboxylicacid in any combination. For example, two or more bacteria, yeastsand/or fungi can be combined with one or more sugars (e.g., glucoseand/or xylose) where the organisms ferment the sugars together,selectively and/or sequentially. Optionally, one organism is added firstand the fermentation proceed for a time, for example, until it stopsfermenting one or more of the sugars, and then a second organism can beadded to further ferment the same sugar or ferment a different sugar.Co-cultures can also be utilized, for example, to tune in a desirableracemic mixture of D and L lactic acid by combining a D-fermenting andL-fermenting organism in an appropriate ratio to form the targetedracemic mixture.

In some embodiments, fermentations utilizing Lactobacillus is preferred.For example, the fermentation of biomass derived glucose byLactobacillus can be very efficient (e.g., fast, selective and with highconversion). In other embodiments the production of lactic acid usingfilamentous fungi is preferred. For example, Rhizopus species canferment glucose aerobically to lactic acid. In addition, some fungi(e.g. R. oryzae and R. arrhizus) produce amylases so that the directfermentation of starches can accomplished without adding externalamylases. Finally some fungi (e.g., R. oryzae) can ferment xylose aswell as glucose where most lactobacillus are not efficient in fermentingpentose sugars.

In some embodiments some bio-additives (e.g., media components) can beadded during the fermentation. for example, bio-additives that can beutilized include yeast extract, rice bran, wheat bran, corn steepliquor, black strap molasses, casein hydrolyzate, vegetable extracts,corn steep solid, ram horn waste, peptides, peptone (e.g.,bacto-peptone, polypeptone), pharmamedia, flower (e.g., wheat flour,soybean flour, cottonseed flour), malt extract, beef extract, tryptone,K₂HPO₄, KH₂PO₄, Na₂HPO₄, NaH₂PO₄, (NH₄)₂PO₄, NH₄OH, NH₄NO, urea,ammonium citrate, nitrilotriacetic acid, MnSO₄.5H₂O, MgSO4.7H₂O,CaCl₂.2H₂O, FeSO₄.7H₂O, B-vitamins (e.g., thiamine, riboflavin, niacin,niacinamide, pantothenic acid, pyridoxine, pyridoxal, pyridoxamine,pyridoxine hydrochloride, biotin, folic acid), amino acids,sodium-L-glutamate, Na₂EDTA, sodium acetate, ZnSO₄.7H₂O, ammoniummolybdate tetrahydrate, CuCl₂, CoCl₂ and CaCO₃. Addition of protease canalso be beneficial during the fermentation. Optionally surfactants suchas Tween 80 and antibiotics such as Chloramphenicol can also bebeneficial. Additional carbon sources, for example, glucose, xylose andother sugars. Antifoaming compounds such as Antifoam 204 can also beutilized.

In some embodiments the fermentation can take from about 8 hours toseveral days. For example, some batch fermentations can take from about1 to about 20 days (e.g., about 1-10 days, about 3-6 days, about 8 hoursto 48 hours, about 8 hours to 24 hours).

In some embodiments the temperature during the fermentation iscontrolled. for example, the temperature can be controlled between about20° C. and 50° C. (e.g., between about 25 and 40° C., between about 30and 40° C., between about 35 and 40° C.). In some case thermophilicorganisms are utilized that operate efficiently above about 50° C., forexample, between about 50° C. and 100° C. (e.g., between about 50-90°C., between about 50 to 80° C., between about 50 to 70° C.).

In some embodiments the pH is controlled, for example, by the additionof an acid or a base. The pH can be optionally controlled to be close toneutral (e.g., between about 4-8, between about 5-7, between about 5-6).Acids, for example, can be protic acids such as sulfuric, phosphoric,nitric, hydrochloride and acetic acids. Bases, for example, can includemetal hydroxides (e.g., sodium and potassium hydroxide), ammoniumhydroxide, and calcium carbonate. Phosphate and other buffers can alsobe utilized.

Fermentation methods include, for example, batch, fed batch, repeatedbatch or continuous reactors. Often batch methods can produce higherconcentrations of lactic acids, while continuous methods can lead tohigher productivities.

Fed batch methods can include adding media components and substrate(e.g., sugars from biomass) as they are depleted. Optionally products,intermediates, side products and/or waste products can be removed asthey are produced. In addition solvent (e.g., water) can be added orremoved to maintain the optimal amount for the fermentation.

Options include cell-recycling. For example, using a hollow fibermembrane to separate cells from media components and products afterfermentation is complete. The cells can then be re-utilized in repeatedbatches. In other optional methods the cells can be supported, forexample, as described in U.S. application Ser. No. 13/293,971, filed onNov. 10, 2011 and U.S. Pat. No. 8,377,668, issued Feb. 19, 2013 theentire disclosures of which are herein incorporated by reference.

The fermentation broth can be neutralized using calcium carbonate orcalcium hydroxide which can form calcium lactate. Calcium lactate issoluble in water (e.g., about 7.9 g/100 mL). The calcium lactate brothcan then be filtered to remove cells and other insoluble materials. Inaddition the broth can be treated with a decolorizing agent. forexample, the broth can be filtered through carbon. The broth is thenconcentrated, e.g., by evaporation of the water optionally under vacuumand/or mild heating, and can be crystallized or precipitated.Acidification, for example, with sulfuric acid, releases the lactic acidback into solution which can be separated (e.g., filtered) from theinsoluble calcium salts, e.g., calcium sulfate. Addition of calciumcarbonate during the fermentation can also serve as a way to reduceproduct inhibition since the calcium lactate is not inhibitory or causesless product inhibition.

Optionally, reactive distillation can also be used to purify D-lacticacid and/or L-lactic acid. For example, methylation of D-lactic acidand/or L-lactic acid provides the methyl ester which can be distillatedto pure ester which can then be hydrolyzed to the acid and methanol thatcan be recycled. Esterification to other esters can also be used tofacilitate the separation. For example, reactions with alcohols to theethyl, propyl, butyl, hexyl, octyl or even esters with more than eightcarbons can be formed and then extracted in a solvent or distilled.

Other alternative D-lactic acid and/or L-lactic acid separationtechnologies include adsorption, for example, on activated carbon,polyvinylpyridine, zeolite molecular sieves and ion exchange resins suchas basic resins. Other methods include ultrafiltration andelectrodialysis.

Precipitation or crystallization of calcium lactate by the addition oforganic solvents is another method for purification. For example,alcohols (e.g., ethanol, propanol, butanol, hexanol), ketones (e.g.,acetone) can be utilized for this purpose.

Similar methods can be utilized for the preparation of otherhydroxy-carboxylic acids. For example, the fermentative methods andprocedures can be applicable for any of the hydroxy-carboxylic acidsdescribed herein.

Polymerization of Hydroxy-Carboylic Acid

Hydroxy-carboxylic acid prepared as described herein can undergo estercondensation to form dimers (e.g., linear and cyclic), trimers,oligomers and polymers. When the poly hydroxy-carboxylic acid ispolylactic acid (PLA) it is therefore a polyester of condensed lacticacid. PLA can be further processed (e.g., grafted, treated, orcopolymerized to form side chains including ionizable groups). Both D, Lisomers of PLA can form polymers and/or they can be copolymerized. Theproperties of the polymer depend on the amounts of the D and L lacticacid incorporated in the structure, as will be discussed further on.

The polymers of hydroxy-carboxylic acids are based on polyester methods.The balance between the hydroxy and the carboxylic acid componentpreferably are close to equimolar. For instance, the mole ratio limit ofhydroxy/carboxylic groups can be in the range of 0.9 to 1.1,alternatively, 0.95 to 1.05, optionally, 0.98 to 1.02 or further 0.99 to1.01. If a hydroxy carboxylic acid has an unequal amount of hydroxysubstituents relative to the carboxylic acid group like malic acid, thanthe appropriate amount of extra diol can be included to obtain a highmolecular weight polymer, if desired.

The polymerization of the PLA is done by the methods described above.

One method for production of high molecular weight PLA is by couplingPLA, for example, made as described above, using chain coupling agents.for example, hydroxyl-terminated PLA can be synthesized by thecondensation of D-lactic acid and/or L-lactic acid in the presence ofsmall amounts of multifunctional hydroxyl compounds such as , ethyleneglycol, propylene glycol, 1,3-propanediol, 1,2-cyclohexanediol,2-butene-1,4-diol, glycerol, 1,4-butanediol, 1,6-hexanediol.Alternatively, carboxyl-terminated PLA can be achieved by thecondensation of D-lactic acid and/or L-lactic acid in the presence ofsmall amounts of multifunctional carboxylic acids such as maleic,succinic, adipic, itaconic and malonic acid. Aromatic diacids are alsocandidates.

These diols and diacids are additives and can be added to the meltstream just prior to flowing the melt stream to the thin film evaporatoror the thin film polymerization/devolatilization device. In order topreserve the condensation parameters of polymer the diol and diacid needto be nearly equimolar. If the alcohol to acid mole ratio departs toomuch from one, then terminated polymers and/or oligomers will beobtained. Thus, the mole ratio of these diols and diacids is from 0.95to 1.05 or optionally 0.975 to 1.025. Also, to preserve the polymerproperties attributed to the poly hydroxy-carboxylic acid the dilutionof the monomers with the diols and diacids should be minimal Sooptionally, the mole ratio of the sum of the aliphatic or aromaticdicarboxylic acid and the aliphatic or aromatic diol to thehydroxy-carboxylic acid monomer of the poly hydroxy-carboxylic acid is0.1 or less. Alternatively the limitation is 0.05 or less.

The timely addition of oligomers of dialcohols or alpha, omega diacidscan lead to a block polymer. This is especially true if the dialcoholsand diacids are added utilizing the thin film evaporator or the thinfilm polymerization/devolatilization device. Examples of oligomers ofdialcohols include low molecular weight polyethylene glycol, 1,2- and1,3 propanediol, 1,4-butanediol and the like.

Inclusion of small quantities of trisubstituted alcohols and triacidscan also lead to beneficial cros slinking of the poly hydroxy carboxylicacid. Amounts of less than 5 wt. %, alternately less than 2.5 wt. % oroptionally less than 1 wt. % may be used to produce a minimally branchedpolymer.

Other additives include chain extending agents that can haveheterofunctional groups that couple either on the carboxylic acid endgroup of the PLA or the hydroxyl end group, for example, 6-hydroxycapricacid, mandelic acid, 4-hydroxybenzoic acid, 4-acetoxybenzoic acid.

Esterification promotion agents can also be combined with D-lactic acidand/or L-lactic acid to increase the molecular weight of PLA. Forexample, ester promotion agents include phosgene, diphosgene,triphosgene dicyclohexylcarbodiimide and carbonyldiimidazole. Somepotentially undesirable side products can be produced by this methodadding purification steps to the process. After final purification, theproduct can be very clean, free of catalysts and low molecular weightimpurities.

The polymer molecular weights can also be increase by the addition ofchain extending agents such as (di)isocyanates, acid chlorides,anhydrides, epoxides, thiirane and oxazoline and orthoester.

Catalysts and promoters that can optionally be used include Protonicacids such as H₃PO₄, H₂SO₄, methane sulfonic acid, p-toluene sulfonicacid, Nafion-H⁺ (sulfonic acid supported/bonded to a polymer thatoptionally may have a tetrafluorethylene backbone), metal catalysts, forexample, include Mg, Al, Ti, Zn, Sn. Some metal oxides that canoptionally catalyze the reaction include TiO₂, ZnO, GeO₂, ZrO₂, SnO,SnO₂, Sb₂O₃. Metal halides, for example, that can be beneficial includeZnCl₂, SnCl₂, SnCl₄. Other metal containing catalysts that canoptionally be used include Mn(AcO)₂, Fe₂(LA)₃, Co(AcO)₂, Ni(AcO)₂,Cu(OA)₂, Zn(LA)₂, Y(OA)₃, Al(i-PrO)₃, Ti(BuO)₄, TiO(acac)₂, (Bu)₂SnO.Combinations and mixtures of the above catalysts can also be used. Forexample, two or more catalysts can be added at one time or sequentiallyas the polymerization progresses. The catalysts can also be removed,replenished and or regenerated during the course of the polymerizationare for repeated polymerizations. Some preferred combinations includeprotonic acids and one of the metal containing catalysts, for example,SnCl₂/p-toluenesulfonic acid. These catalysts are normally added betweensteps 2 and 3 of the polymerization process described above.

During the step 1 of the polymerization process, for example, especiallyat the beginning of the polymerization when the concentration of lacticacid is high and water is being formed at a rapid rate, the lacticacid/water azeotropic mixture can be condensed and made to pass throughmolecular sieves to dehydrate the lactic acid which is then returned tothe reaction vessel.

Copolymers can be produced by adding monomers other than lactic acidduring the azeotropic condensation reaction. For example, any of themultifunctional hydroxyl, carboxylic compounds or the heterofunctionalcompounds that can be used as coupling agents for low molecular weightPLA can also be used as co-monomers in the azeotropic condensationreaction.

In addition to homopolymer, copolymerization with other cyclic monomersand non-cyclic monomers such as glycolide, caprolactone, valerolactone,dioxypenone, trimethyl carbonate, 1,4-benzodioxepin-2,5-(3H)-dioneglycosalicylide, 1,4-benzodioxepin-2,5-(3H, 3-methyl)-dioneLactosalicylide, dibenzo-1,5 dioxacin-6-12-dione disalicylide,morpholine-2,5-dione, 1,4-dioxane-2,5-dione glycolide, oxepane-2-oneε-caprolactone, 1,3-dioxane-2-one trimethylene carconate,2,2-dimethyltrimethylene carbonate, 1,5-dioxepane-2-one,1,4-dioxane-2-one p-dioxanone, gamma-butyrolactone, beta-butyrolactone,beta-me-delta-valerolactone, 1,4-dioxane-2,3-dione ethylene oxalate,3-[benzyloxycarbonyl methyl]-1,4-dioxane-2,5-dione, ethyleneoxide,propylene oxide, 5,5′(oxepane-2-one),2,4,7,9-tetraoxa-spiro[5,5]undecane-3,8-dione Spiro-bid-dimethylenecaronate can produce co-polymers. Copolymers can also be produced byadding monomers such as the multifunctional hydroxyl, carboxyliccompounds or the heterofunctional compounds that can be used as couplingagents for low molecular weight PLA.

Copolymers may also be formed with other hydroxy-carboxylic acids. Thecomonomers include 3-hydroxyvalerate, 4-hydroxybutyrate which are gammaand delta hydroxy-carboxylic acids, respectively. Another monomer whichcan be copolymerized is 3-hydroxybutyrate (beta substituted). Thesemonomers can be copolymerized or blended as polymers with a polylacticacid polymer to form a polymer blend.

In addition to chemical method, D-lactic acid and/or L-lactic acid canbe polymerized by LA-polymerizing enzymes and organisms.

Poly Hydroxyl-Carboxylic Sterochemistry

Mechanical and thermal properties of the homopolymer ofhydroxyl-carboxylic acid are largely determined by the molecular weightand stereochemical composition of the backbone. For lactic acid thestereochemical composition of the backbone can be controlled by thechoice and ratios of monomers; D-Lactic acid, L-Lactic acid oralternatively D-Lactide, L-Lactide or meso-Lactide. This stereochemicalcontrol allows the formation of random or block stereocopolymers. Themolecular weight of the polymers can be controlled, for example, asdiscussed above. The ability to control the stereochemical architectureallows, for example, precise control over the speed and degree ofcrystallinity, the mechanical properties, and the melting point andglass transition temperatures of the material.

The degree of crystallinity of PLA influences the hydrolytic stabilityof the polymer, and therefore, the biodegradability of the polymer. Forexample, highly crystalline PLA can take from months to years todegrade, while amorphous samples can be degraded in a few weeks to a fewmonths. This behavior is due in part to the impermeability of thecrystalline regions of PLA. Table 1 shows some of the thermal propertiesof some PLA of similarly treated samples. The information in Table 1comes from Polylactic Acid: PLA Biopolymer Technology and Applications,Lee Tin Sin, A. R. Rahmat, W. A. Rahman; Dec. 31, 2012. The percentcrystallinity can be calculated by using data form the table andapplying the equation.

${\% \; \chi_{c}} = {\frac{\left( {{\Delta \; H_{m}} - {\Delta \; H_{c}}} \right)}{93} \cdot 100}$

Where ΔH_(m) is the melting enthalpy in J/g, ΔH_(c) is thecrystallization enthalpy in J/g and 93 is the crystallization enthalpyof a totally crystalline PLA sample in J/g.

As can be calculated from the data in the table, the crystallinity isdirectly proportional to the molecular weight of the pure L or pure Dstereopolymer. The DL steroeoisomer (e.g., an atactic polymer) isamorphous.

TABLE 1 Thermal properties of PLA Isomer M_(n) × M_(w)/ T_(g) T_(m) ΔHT_(c) ΔH type 10³ M_(n) (° C.) (° C.) (J/g) (° C.) (J/g) L 4.7 1.09 45.6157.8 55.5 98.3 47.8 DL 4.3 1.90 44.7 — — — — L 7.0 1.09 67.9 159.9 58.8108.3 48.3 DL 7.3 1.16 44.1 — — — — D 13.8 1.19 65.7 170.3 67.0 107.652.4 L 14.0 1.12 66.8 173.3 61 

  110.3 48.1 D 16.5 1.20 69.1 173.5 64.6 109.0 51.6 L 16.8 1.32 58.6173.4 61.4 105.0 38.1

indicates data missing or illegible when filed

Calculated crystallinities are in order top to bottom: 8.2%, 0%, 11.3%,0%, 15.7%, 13.8%, 14.0% and 25%.

The thermal treatment of samples, for example, rates of melting,recrystallization, and annealing history, can in part determine theamount of crystallization. Therefore, comparisons of the thermal,chemical and mechanical properties of PLS polymers should generally bemost meaningful for polymers with a similar thermal history.

The pure L-PLA or D-PLA has a higher tensile strength and low elongationand consequently has a higher modulus than DL-PLA. Values for L-PLA varygreatly depending on how the material is made e.g., tensile strengths of30 to almost 400 MPa, and tensile modulus between 1.7 to about 4.5 GPa.

Poly Hydroxy-Carboxylic Acid Copolymers, Crosslinking and Grafting

Variation of the poly hydroxy-carboxylic acids by the formation ofcopolymers as discussed above also has a very large influence on theproperties, for example, by disrupting and decreasing the crystallinityand modulating the glass transition temperatures. For example, polymerswith increased flexibility, improved hydrophilicity, betterdegradability, better biocompatibility, better tensile strengths,improved elongations properties can be produced.

The thin film polymerization/devolatilization device can be the processwhere these co-monomers can be added to the melt polymer.

The co-monomers to produce copolymers with poly hydroxy-carboxylicacids. In most cases, the improvements are correlated with a decrease inthe glass transition temperature. A few monomers can increase the glasstransition temperature of poly hydroxyl-carboxylic acid. For example,lactones of salicylic acids can have homopolymer glass transitiontemperatures between about 70 and 110° C. and be copolymerize with thehydroxyl-carboxylic acid.

Morpholinediones, which are half alpha-hydroxy-carboxylic acids and halfalpha-amino acids co-polymerize with lactide to give high molecularweight random co-polymers with lower glass transition temperatures(e.g., following the Flory-Fox equation). For example, morpholinedionesmade up of glycine and lactic acid (6-methyl-2,5-morpholinedione) whencopolymerized with lactide can give a polymer with glass transitiontemperatures of 109 and 71° C. for a 50 and 75 mol % lactic acidrespectively in the polymer. Morpholinediones have been synthesizedusing glycolic acid or lactic acid and most of the alpha amino acids(e.g., glycine, alanine, aspartic acid, lysine, cysteine, valine andleucine). In addition to lowering the glass transition temperature andimproving mechanical properties, the use of functional amino acids inthe synthesis of morpholinediones is an effective way of incorporatingfunctional pendent groups into the polymer.

As an example, copolymers of glycolide and lactide can be useful asbiocompatible surgical sutures due to increased flexibility andhydrophilicity. The higher melting point of 228° C. and Tg of 37° C. forpolyglycolic acid can produce a range of amorphous co-polymers withlower glass transition temperatures than poly lactic acid. Anothercopolymerization example is copolymerization with e-caprolactone whichcan yield tough polymers with properties ranging from ridged plastics toelastomeric rubbers and with tensile strengths ranging from 80 to 7000psi, and elongations over 400%. Co-polymers ofbeta-methyl-gamma-valerolactone have been reported to producerubber-like properties. Co-polymers with polyethers such aspoly(ethylene oxide), poly(propylene oxide) and poly(tetramethyleneoxide) are biodegradable, biocompatible and flexible polymers.

Some additional useful monomers that can be copolymerized with lactideinclude 1,4-benzodioxepin-2,3(H)-dione glycosalicylide;1.3-benzodioxepin-2,5-(3H, 3-methyl)-dione Lactosalicylide;dibenzo-1,5-dioxacin-6,12-dione disalicylide; morpholine-2,5-dione,1,4-dioxane-2,5-dione, glycolide; oxepane-2-one trimethylene carbonate;2,2-dimethyltrimethylene carbonate; 1,5-dioxepane-2-one;1,4-dioxane-2-one p-dioxanone; gamma-butyrolactone; beta-butyrolactone;beta-methyl-delta-valerolactone; beta-methyl-gamma-valerolactone;1,4-dioxane-2,3-dione ethylene oxalate; 3[(benzyloxyacarbonyl)methyl]-1,4-dioxane-2,5-dione; ethylene oxide;propylene oxide, 5,5′-(oxepane-2-one) and2,4,7,9-tetraoxa-spiro[5,5]undecane-3,8-dione Spiro-bis-dimethylenecaronate.

Hydroxy-carboxylic acids polymers and co-polymers can be modified bycrosslinking additives. Crosslinking can affect the thermal andrheological properties without necessarily deteriorating the mechanicalproperties. For example, 0.2 mol %5,5′-bis(oxepane-2-one)(bis-ε-caprolactone)) and 0.1-0.2 mol %spiro-bis-dimethylene carbonate cross linking. Free radical hydrogenabstraction reactions and subsequent polymer radical recombination is aneffective way of inducing crosslinks into a polymer. Radicals can begenerated, for example, by high energy electron beam and otherirradiation (e.g., between about 0.01 Mrad and 15 Mrad, e.g., betweenabout 0.01-5 Mrad, between about 0.1-5 Mrad, between about 1-5 Mrad).For example, irradiation methods and equipment are described in detailbelow.

Alternatively or in addition, peroxide additives, such as organicperoxides are effective radical producing and cross linking agents. Forexample, peroxides that can be used include hydrogen peroxide, dicumylperoxide; benzoyl peroxide; 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane;tert-butylperoxy 2-ethylhexyl carbonate; tert-amylperoxy-2-ethylhexanoate; 1,1-di(tert-amylperoxy)cyclohexane; tert-amylperoxyneodecanoate; tert-amyl peroxybenzoate; tert-amylperoxy2-ethylhexyl carbonate; tert-amyl peroxyacetate;2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane; tert-butylperoxy-2-ethylhexanoate; 1,1-di(tert-butylperoxy)cyclohexane; tert-butylperoxyneodecanoate; tert-butyl peroxyneoheptanoate; tert-butylperoxydiethylacetate;1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane;3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane;di(3,5,5-trimethylhexanoyl)peroxide; tert-butyl peroxyisobutyrate;tert-butyl peroxy-3,5,5-trimethylhexanoate; di-tert-butyl peroxide;tert-butylperoxy isopropyl carbonate; tert-butyl peroxybenzoate;2,2-di(tert-butylperoxy)butane; di(2-ethylhexyl) peroxydicarbonate;di(2-ethylhexyl) peroxydicarbonate; tert-butyl peroxyacetate; tert-butylcumyl peroxide; tert-amylhydroperoxide; 1,1,3,3-tetramethylbutylhydroperoxide, and mixtures of these. The effective amounts can vary,for example, depending on the peroxide, crosslinking reaction conditionsand the desired properties (e.g., amount of crosslinking). For example,crosslinking agents can be added from between about 0.01-10 wt. % (e.g.,about 0.1-10 wt. %, about 0.01-5 wt. %, about 0.1-1 wt. %, about 1-8 wt.%, about 4-6 wt. %). For example, peroxides such as 5.25 wt. % dicumylperoxide and 0.1% benzoyl peroxide are effective radical producing andcross linking agents for poly hydroxy-carboxylic acids and polyhydroxy-carboxylic acids derivatives. The peroxide crosslinking agentscan be added to polymers as solids, liquids or solutions, for example,in water or organic solvents such as mineral spirits. In additionradical stabilizers can be utilized.

Crosslinking can also be effectively accomplished by the incorporationof unsaturation in the polymer chain either by: initiation withunsaturated alcohols such as hydroxyethyl methacrylate or2-butene-1,4-diol; the post reaction with unsaturated anhydrides such asmaleic anhydride to transform the hydroxyl chain end; orcopolymerization with unsaturated epoxides such as glycidylmethacrylate.

In addition to cross linking, grafting of functional groups and polymersto a hydroxy-carboxylic acid polymer or co-polymer is an effectivemethod of modifying the polymer properties. For example, radicals can beformed as described above and a monomer, functionalizing polymer orsmall molecule. For example, irradiation or treatment with a peroxideand then quenching with a functional group containing an unsaturatedbond can effectively functionalize the poly hydroxy-carboxylic acidbackbone.

The thin film polymerization/devolatilization device can be the processwhere these crosslinking and/or the grafting component may be added tothe melt polymer.

Poly Hydroxy-Carboxylic Acids Blending

Poly hydroxy-carboxylic acids can be blended with other polymers asmiscible or immiscible compositions. For immiscible blends thecomposition can be one with the minor component (e.g., below about 30wt. %) as small (e.g., micron or sub-micron) domains in the majorcomponent. When one component is about 30 to 70 wt. % the blend forms aco-continuous morphology (e.g., lamellar, hexagon phases or amorphouscontinuous phases). The polymers to be blended with the polyhydroxy-carboxylic acids may be random, linear copolymer, diblock,graft, star, and branched polymers.

Blending can be accomplished by melt mixing above the glass transitiontemperature of the amorphous polymer components. The thin filmevaporator and thin film polymerization/devolatilization device can beused for blending the polymers. Also, screw extruders (e.g., singlescrew extruders, co-rotating twin screw extruders, counter rotating twinscrew extruders) can be useful for this. For hydroxy-carboxylic acidpolymers and co-polymers temperatures below about 200° C. can be used toavoid thermal degradation (e.g. below about 180° C.).

Polyethylene oxide (PEO) and polypropylene oxide (PPO) can be blendedwith poly hydroxy-carboxylic acids. Lower molecular weight glycols(300-1000 Mw) are miscible with poly hydroxy-carboxylic acids while PPObecomes immiscible at higher molecular weight. These polymers,especially PEO, can be used to increase the water transmission andbio-degradation rate of poly hydroxy-carboxylic acids. They can also beused as polymeric plasticizers to lower the modulus and increaseflexibility of poly hydroxy-carboxylic acids. High molecular weight PEG(20,000) is miscible in poly hydroxy-carboxylic acids up to about 50%,but above that level the PEG crystallizes, reducing the ductility of theblend.

Polyvinyl acetate (PVA) is miscible with poly hydroxy-carboxylic acidsin most concentrations. For PVA and poly lactic acid blends only one Tgis observed at all blend ratios, with a constant decrease to about 37°C. at 100% PVA. Low levels of PVA (5-10%) increase the tensile strengthand % elongation of poly hydroxy-carboxylic acids while significantlyreducing the rate of weight loss during bio-degradation.

Blends of poly hydroxy-carboxylic acids and polyolefins (polypropyleneand polyethylene) result in incompatible systems with poor physicalproperties due to the poor interfacial compatibility and highinterfacial energy. However, the interfacial energy can be lowered, forexample, by the addition of third component compatibilizers, such asglycidyl methacrylate grafted polyethylene. (irradiation would probablywork) Polystyrene and high impact polystyrene resins are also non-polarand blends with poly hydroxy-carboxylic acids are generally notcompatible.

Poly hydroxy-carboxylic acids and acetals can be blended makingcompositions with useful properties. For example, these blends havegood, high transparency.

In general, poly hydroxy-carboxylic acids are miscible with polymethylmethacrylate and many other acrylates and copolymers of (meth)acrylates.Drawn films of polymethyl methacrylate/poly hydroxy-carboxylic acidsblends can be transparent and have high elongation.

Polycarbonate can be combined with poly hydroxy-carboxylic acids up toabout a 50 wt. % composition of polycarbonate. The compositions havehigh heat resistance, flame resistance and toughness and haveapplications, for example, in consumer electronics such as laptops.About 50 wt. % polycarbonate, the processing temperatures approach thedegradation temperature of poly hydroxy-carboxylic acids.

Acrylonitrile butadiene styrene (ABS) can be blended with polyhydroxy-carboxylic acids although the polymers are not miscible. Thiscombination less brittle material than poly hydroxy-carboxylic acids andprovides a way to toughen poly hydroxy-carboxylic acids.

Poly(propylene carbonate) can be blended with poly hydroxy-carboxylicacids providing a biodegradable composite since both polymers arebiodegradable.

Poly hydroxy-carboxylic acids can also be blended with poly(butylenesuccinate). Blends can impart thermal stability and impact strength tothe poly hydroxy-carboxylic acids.

PEG, poly propylene glycol, poly(vinyl acetate), anhydrides (e.g.,maleic anhydride) and fatty acid esters have been added as plasticizersand/or compatibilizers.

Blending can also be accomplished with the application of irradiation,including irradiation and quenching. For example, irradiation orirradiation and quenching as described herein applied to biomass can beapplied to the irradiation of poly hydroxy-carboxylic acids and polyhydroxy-carboxylic acids copolymers for any purpose, for example,before, after and/or during blending. This treatment can aid in theprocessing, for example, making the polymers more compatible and/ormaking/breaking bonds within the polymer and/or blended additive (e.g.,polymer, plasticizer). For example, between about 0.1 Mrad and 150 Mradfollowed by quenching of the radicals by the addition of fluids or gases(e.g., oxygen, nitrous oxide, ammonia, liquids), using pressure, heat,and/or the addition of radical scavengers. Quenching of biomass that hasbeen irradiated is described in U.S. Pat. No. 8,083,906 to Medoff, theentire disclosure of which is incorporate herein by reference, and theequipment and processes describe therein can be applied to polyhydroxy-carboxylic acids and poly hydroxy-carboxylic acids derivatives.Irradiation and extruding or conveying of the poly hydroxy-carboxylicacids or poly hydroxy-carboxylic acids copolymers can also be utilized,for example, as described for the treatment of biomass in U.S.application Ser. No. 13/099,151 filed on May 2, 2011 published as USApplication US 2011-0262985 the entire disclosure of which isincorporated herein by reference.

Poly Hydroxy-Carboxylic Acid Composites

Poly hydroxy-carboxylic acids polymers, co-polymers and blends can becombined with synthetic and/or natural materials. For example, polyhydroxy-carboxylic acids and any poly hydroxy-carboxylic acidsderivative (e.g., poly hydroxy-carboxylic acids copolymers, polyhydroxy-carboxylic acids blends, grated poly hydroxy-carboxylic acids,cross-linked poly hydroxy-carboxylic acids) can be combined withsynthetic and natural fibers. For example, protein, starch, cellulose,plant fibers (e.g., abaca, leaf, skin, bark, kenaf fibers), inorganicfillers, flax, talc, glass, mica, saponite and carbon fibers. This canprovide a material with, for example, improved mechanical properties(e.g., toughness, harness, strength) and improved barrier properties(e.g., lower permeability to water and/or gasses).

Nano composites can also be made by dispersing inorganic or organicnanoparticles into either a thermoplastic or thermoset polymer.Nanoparticles can be spherical, polyhedral, two dimensional nanofibersor disc-like nanoparticles. For example, colloidal or microcrystallinesilica, alumina or metal oxides (e.g., TiO₂); carbon nanotubes; clayplatelets.

Composites can be prepared similarly to polymer blends, for example,utilizing screw extrusion and/or injection molding. Irradiation asdescribed herein can also be applied to the composites, during, after orbefore their formation. For example, irradiation of the polymer andcombination with the synthetic and/or natural materials, or irradiationof the synthetic and/or natural materials and combination with thepolymer, or irradiation of both the polymer and synthetic and/or naturalmaterial and then combining, or irradiating the composite after it hasbeen combined, with or without further processing.

Poly Hydroxy-Carboxylic Acids with Plasticizers and Elastomers

In addition to the blends previously discussed, poly hydroxy-carboxylicacids and poly hydroxy-carboxylic acids derivatives can be combined withplasticizers.

For example, as described in J. Appl. Polym. Sci. 66: 1507-1513, 1997,poly lactic acid can be blended with monomeric and oligomericplasticizers in order to enhance its flexibility and thereby overcomeits inherent brittleness. Monomeric plasticizers, such as tributylcitrate, and diethyl bishydroxymethyl malonate, DBM, can drasticallydecreased the T_(g) of PLA. Increasing the molecular weight of theplasticizers by synthesizing oligoesters and oligoesteramides can resultin blends with T_(g) depressions slightly smaller than with themonomeric plasticizers. The compatibility with poly hydroxy-carboxylicacids can be dependent on the molecular weight of the oligomers and onthe presence of polar groups (e.g., amide groups, hydroxyl groups,ketones, esters) that can interact with the poly hydroxy-carboxylicacids chains. The materials can retain a high flexibility andmorphological stability over long periods of time, for example, whenformed into films.

Citrate esters can also be used as plasticizers with polyhydroxy-carboxylic acids. Films can be extruded, for example, using asingle or twin-screw extruder with plasticizer contents (citrate estersor others described herein) of between about 1 and 40 wt. % (e.g., about5-30 wt. %, about 5-25 wt. %, about 5-15 wt. %). Plasticizers such ascitrate esters can be effective in reducing the glass transitiontemperature and improving the elongation at break. The plasticizingefficiency can be higher for the intermediate-molecular-weightplasticizers. The addition of plasticizers can modulate the enzymaticdegradation of poly hydroxy-carboxylic acids. For example,lower-molecular-weight citrates can increase the enzymatic degradationrate of poly hydroxy-carboxylic acids and the higher-molecular-weightcitrates can decreased the degradation rate as compared with that ofunplasticized poly hydroxy-carboxylic acids.

Preparation of poly hydroxy-carboxylic acids/elastomer blends can alsobe prepared by melt blending technique, for example, as described in theJournal of Elastomers and Plastics, Jan. 3, 2013; polyhydroxy-carboxylic acids and biodegradable elastomer can be melt blendedand molded in an injection molding machine. The melting temperature candecrease as the amount of elastomer increases. Additionally, thepresence of elastomer can modulate the crystallinity of polyhydroxy-carboxylic acids, for example, increasing the crystallinity bybetween about 1 and 30% (e.g., between about 1 to 20%, between about 5and 15%). The complex viscosity and storage modulus of polyhydroxy-carboxylic acids melt can decrease upon addition of elastomer.The elongation at break can increase as the content of elastomerincreased while Young's modulus and tensile strength often decrease dueto the addition of elastomer.

It has been observed that the cold crystallization temperature of theblends decreased as the weight fraction of elastomer increased as wellas the onset temperature of cold crystallization also shifted to lowertemperature. For example, as reported in the Journal of PolymerResearch, February 2012, 19:9818. In non-isothermal crystallizationexperiments, the crystallinity of poly lactic acid increased with adecrease in the heating and cooling rate. The melt crystallization offor example, poly lactic acid appeared in the low cooling rate (1, 5 and7.5° C./min) The presence of small amounts of elastomer can alsoincrease the crystallinity of poly lactic acid. The DSC thermogram atramp of 10° C./min showed the maximum crystallinity of poly lactic acidis 36.95% with 20 wt. % elastomer contents in blends. In isothermalcrystallization, the cold crystallization rate increased with increasingcrystallization temperature in the blends. The Avrami analysis showedthat the cold crystallization was in two stages process and it wasclearly seen at low temperature. The Avrami exponent (n) at first stagewas varying from 1.59 to 2 which described a one-dimensionalcrystallization growth with homogeneous nucleation, whereas at secondstage was varying from 2.09 to 2.71 which described the transitionalmechanism to three dimensional crystallization growth with heterogeneousnucleation mechanism. The equilibrium melting point of poly lactic acidwas also evaluated at 176° C.

Some examples of elastomers that can be combined with PLA include:Elastomer NPEL001, Polyurethane elastomers (5-10%), Functionalizedpolyolefin elastomers, Blendex® (e.g., 415, 360, 338), PARALOID™ KM 334,BTA 753, EXL 3691A, 2314, Ecoflex® Supersoft Silicone Bionolle® 3001,Pelleethane® 2102-75A, Kraton® FG 1901X, Hytrel® 3078, and mixtures ofthese. Mixtures with any other elastomer, for example, as describedherein can also be used.

Some examples of plasticizers that can be combined with polyhydroxy-carboxylic acids include: Triacetin, Glycerol triacetate,Tributyl citrate, Polyethylene glycol, GRINDSTED® SOFT-N-SAFE (Aceticacid ester of monoglycerides) made from fully hydrogenated castor oiland combinations of these. Mixtures with other plasticizers, forexample, as described herein can also be used.

The main characteristic of elastomer materials is the high elongationand flexibility or elasticity of these materials, against its breakingor cracking.

Depending on the distribution and degree of the chemical bonds of thepolymers, elastomeric materials can have properties or characteristicssimilar to thermosets or thermoplastics, so elastomeric materials can beclassified into: Thermoset Elastomers (e.g., do not melt when heated)and Thermoplastic Elastomers (e.g., melt when heated). Some propertiesof elastomer materials: cannot melt, before melting they pass into agaseous state; swell in the presence of certain solvents; are generallyinsoluble; are flexible and elastic; lower creep resistance than thethermoplastic materials.

Examples of applications of elastomer materials describe herein are:possible substitutes or replacements for natural rubber (e.g., materialused in the manufacture of gaskets, shoe heels); possible substitutes orreplacements for polyurethanes (e.g., for use in the textile industryfor the manufacture of elastic clothing, for use as foam, and for use inmaking wheels); possible substitutes or replacements for polybutadiene(e.g., elastomer material used on the wheels or tires of vehicles);possible substitutes or replacements for neoprene (e.g., used for themanufacture of wetsuits , wire insulation, industrial belts); possiblesubstitutes or replacements for silicone (e.g., pacifiers, medicalprostheses, lubricants). In addition, the materials described herein canbe used as substitutes for polyurethane and silicon adhesives.

Flavors, Fragrances and Colors

Any of the products and/or intermediates described herein, for example,poly hydroxy-carboxylic acids, poly hydroxy-carboxylic acids derivatives(e.g., poly hydroxy-carboxylic acids copolymers, poly hydroxy-carboxylicacids composites, cross-linked poly hydroxy-carboxylic acids, graftedpoly hydroxy-carboxylic acids, poly hydroxy-carboxylic acids blends orany other poly hydroxy-carboxylic acids containing material prepared asdescribed herein) can also be combined with flavors, fragrances colorsand/or mixtures of these. For example, any one or more of (optionallyalong with flavors, fragrances and/or colors) sugars, organic acids,fuels, polyols, such as sugar alcohols, biomass, fibers and composites,hydroxyl-carboxylic acids, lactic acid, poly hydroxy-carboxylic acids,poly hydroxy-carboxylic acids derivatives can be combined with (e.g.,formulated, mixed or reacted) or used to make other products. Forexample, one or more such product can be used to make soaps, detergents,candies, drinks (e.g., cola, wine, beer, liquors such as gin or vodka,sports drinks, coffees, teas), pharmaceuticals, adhesives, sheets (e.g.,woven, none woven, filters, tissues) and/or composites (e.g., boards).For example, one or more such products can be combined with herbs,flowers, petals, spices, vitamins, potpourri, or candles. For example,the formulated, mixed or reacted combinations can haveflavors/fragrances of grapefruit, orange, apple, raspberry, banana,lettuce, celery, cinnamon, vanilla, peppermint, mint, onion, garlic,pepper, saffron, ginger, milk, wine, beer, tea, lean beef, fish, clams,olive oil, coconut fat, pork fat, butter fat, beef bouillon, legume,potatoes, marmalade, ham, coffee and cheeses.

Flavors, fragrances and colors can be added in any amount, such asbetween about 0.01 wt. % to about 30 wt. %, e.g., between about 0.05 toabout 10, between about 0.1 to about 5, or between about 0.25 wt. % toabout 2.5 wt. %. These can be formulated, mixed and or reacted (e.g.,with any one of more product or intermediate described herein) by anymeans and in any order or sequence (e.g., agitated, mixed, emulsified,gelled, infused, heated, sonicated, and/or suspended). Fillers, binders,emulsifier, antioxidants can also be utilized, for example, proteingels, starches and silica.

The flavors, fragrances and colors can be natural and/or syntheticmaterials. These materials can be one or more of a compound, acomposition or mixtures of these (e.g., a formulated or naturalcomposition of several compounds). Optionally, the flavors, fragrances,antioxidants and colors can be derived biologically, for example, from afermentation process (e.g., fermentation of saccharified materials asdescribed herein). Alternatively, or additionally these flavors,fragrances and colors can be harvested from a whole organism (e.g.,plant, fungus, animal, bacteria or yeast) or a part of an organism. Theorganism can be collected and or extracted to provide color, flavors,fragrances and/or antioxidant by any means including utilizing themethods, systems and equipment described herein, hot water extraction,chemical extraction (e.g., solvent or reactive extraction includingacids and bases), mechanical extraction (e.g., pressing, comminuting,filtering), utilizing an enzyme, utilizing a bacteria such as to breakdown a starting material, and combinations of these methods. Thecompounds can be derived by a chemical reaction, for example, thecombination of a sugar (e.g., as produced as described herein) with anamino acid (Maillard reaction). The flavor, fragrance, antioxidantand/or color can be an intermediate and or product produced by themethods, equipment or systems described herein, for example, and esterand a lignin derived product.

Some examples of flavor, fragrances or colors are polyphenols.Polyphenols are pigments responsible for the red, purple and blue colorsof many fruits, vegetables, cereal grains, and flowers. Polyphenols alsocan have antioxidant properties and often have a bitter taste. Theantioxidant properties make these important preservatives. On class ofpolyphenols are the flavonoids, such as anthrocyanins, flavonols,flavan-3-ols, flavones, flavanones and flavonoids. Other phenoliccompounds that can be used include phenolic acids and their esters, suchas chlorogenic acid and polymeric tannins

Inorganic compounds, minerals or organic compounds can be used, forexample, titanium dioxide, cadmium yellow (E.g., CdS), cadmium orange(e.g., CdS with some Se), alizarin crimson (e.g., synthetic ornon-synthetic rose madder), ultramarine (e.g., synthetic ultramarine,natural ultramarine, synthetic ultramarine violet), cobalt blue, cobaltyellow, cobalt green, viridian (e.g., hydrated chromium(III)oxide),chalcophylite, conichalcite, cornubite, cornwallite and liroconite.

Some flavors and fragrances that can be utilized include ACALEA TBHQ,ACET C-6, ALLYL AMYL GLYCOLATE, ALPHA TERPINEOL, AMBRETTOLIDE, AMBRINOL95, ANDRANE, APHERMATE, APPLELIDE, BACDANOL®, BERGAMAL, BETA IONONEEPDXIDE, BETA NAPHTHYL ISO-BUTYL ETHER, BICYCLONONALACTONE, BORNAFIX®,CANTHOXAL, CASHMERAN®, CASHMERAN® VELVET, CASSIFFIX®, CEDRAFIX,CEDRAMBER®, CEDRYL ACETATE, CELESTOLIDE, CINNAMALVA, CITRAL DIMETHYLACETATE, CITROLATE™, CITRONELLOL 700, CITRONELLOL 950, CITRONELLOLCOEUR, CITRONELLYL ACETATE, CITRONELLYL ACETATE PURE, CITRONELLYLFORMATE, CLARYCET, CLONAL, CONIFERAN, CONIFERAN PURE, CORTEX ALDEHYDE50% PEOMOSA, CYCLABUTE, CYCLACET®, CYCLAPROP®, CYCLEMAX™, CYCLOHEXYLETHYL ACETATE, DAMASCOL, DELTA DAMASCONE, DIHYDRO CYCLACET, DIHYDROMYRCENOL, DIHYDRO TERPINEOL, DIHYDRO TERPINYL ACETATE, DIMETHYLCYCLORMOL, DIMETHYL OCTANOL PQ, DIMYRCETOL, DIOLA, DIPENTENE, DULCINYL®RECRYSTALLIZED, ETHYL-3-PHENYL GLYCIDATE, FLEURAMONE, FLEURANIL, FLORALSUPER, FLORALOZONE, FLORIFFOL, FRAISTONE, FRUCTONE, GALAXOLIDE® 50,GALAXOLIDE® 50 BB, GALAXOLIDE® 50 IPM, GALAXOLIDE® UNDILUTED,GALBASCONE, GERALDEHYDE, GERANIOL 5020, GERANIOL 600 TYPE, GERANIOL 950,GERANIOL 980 (PURE), GERANIOL CFT COEUR, GERANIOL COEUR, GERANYL ACETATECOEUR, GERANYL ACETATE, PURE, GERANYL FORMATE, GRISALVA, GUAIYL ACETATE,HELIONAL™, HERBAC, HERBALIME™, HEXADECANOLIDE, HEXALON, HEXENYLSALICYLATE CIS 3-, HYACINTH BODY, HYACINTH BODY NO. 3, HYDRATROPICALDEHYDE.DMA, HYDROXYOL, INDOLAROME, INTRELEVEN ALDEHYDE, INTRELEVENALDEHYDE SPECIAL, IONONE ALPHA, IONONE BETA, ISO CYCLO CITRAL, ISO CYCLOGERANIOL, ISO E SUPER®, ISOBUTYL QUINOLINE, JASMAL, JESSEMAL®,KHARISMAL®, KHARISMAL® SUPER, KHUSINIL, KOAVONE®, KOHINOOL®, LIFFAROME™,LIMOXAL, LINDENOL™, LYRAL®, LYRAME SUPER, MANDARIN ALD 10% TRI ETH,CITR, MARITIMA, MCK CHINESE, MEIJIFF™, MELAFLEUR, MELOZONE, METHYLANTHRANILATE, METHYL IONONE ALPHA EXTRA, METHYL IONONE GAMMA A, METHYLIONONE GAMMA COEUR, METHYL IONONE GAMMA PURE, METHYL LAVENDER KETONE,MONTAVERDI®, MUGUESIA, MUGUET ALDEHYDE 50, MUSK Z4, MYRAC ALDEHYDE,MYRCENYL ACETATE, NECTARATE™, NEROL 900, NERYL ACETATE, OCIMENE,OCTACETAL, ORANGE FLOWER ETHER, ORIVONE, ORRINIFF 25%, OXASPIRANE,OZOFLEUR, PAMPLEFLEUR®, PEOMOSA, PHENOXANOL®, PICONIA, PRECYCLEMONE B,PRENYL ACETATE, PRISMANTOL, RESEDA BODY, ROSALVA, ROSAMUSK, SANJINOL,SANTALIFF™, SYVERTAL, TERPINEOL,TERPINOLENE 20, TERPINOLENE 90 PQ,TERPINOLENE RECT., TERPINYL ACETATE, TERPINYL ACETATE JAX, TETRAHYDRO,MUGUOL®, TETRAHYDRO MYRCENOL, TETRAMERAN, TIMBERSILK™, TOBACAROL,TRIMOFIX® O TT, TRIPLAL®, TRISAMBER®, VANORIS, VERDOX™, VERDOX™ HC,VERTENEX®, VERTENEX® HC, VERTOFIX® COEUR, VERTOLIFF, VERTOLIFF ISO,VIOLIFF, VIVALDIE, ZENOLIDE, ABS INDIA 75 PCT MIGLYOL, ABS MOROCCO 50PCT DPG, ABS MOROCCO 50 PCT TEC, ABSOLUTE FRENCH, ABSOLUTE INDIA,ABSOLUTE MD 50 PCT BB, ABSOLUTE MOROCCO, CONCENTRATE PG, TINCTURE 20PCT, AMBERGRIS, AMBRETTE ABSOLUTE, AMBRETTE SEED OIL, ARMOISE OIL 70 PCTTHUYONE, BASIL ABSOLUTE GRAND VERT, BASIL GRAND VERT ABS MD, BASIL OILGRAND VERT, BASIL OIL VERVEINA, BASIL OIL VIETNAM, BAY OIL TERPENELESS,BEESWAX ABS N G, BEESWAX ABSOLUTE, BENZOIN RESINOID SIAM, BENZOINRESINOID SIAM 50 PCT DPG, BENZOIN RESINOID SIAM 50 PCT PG, BENZOINRESINOID SIAM 70.5 PCT TEC, BLACKCURRANT BUD ABS 65 PCT PG, BLACKCURRANTBUD ABS MD 37 PCT TEC, BLACKCURRANT BUD ABS MIGLYOL, BLACKCURRANT BUDABSOLUTE BURGUNDY, BOIS DE ROSE OIL, BRAN ABSOLUTE, BRAN RESINOID, BROOMABSOLUTE ITALY, CARDAMOM GUATEMALA CO2 EXTRACT, CARDAMOM OIL GUATEMALA,CARDAMOM OIL INDIA, CARROT HEART, CASSIE ABSOLUTE EGYPT, CASSIE ABSOLUTEMD 50 PCT IPM, CASTOREUM ABS 90 PCT TEC, CASTOREUM ABS C 50 PCT MIGLYOL,CASTOREUM ABSOLUTE, CASTOREUM RESINOID, CASTOREUM RESINOID 50 PCT DPG,CEDROL CEDRENE, CEDRUS ATLANTICA OIL REDIST, CHAMOMILE OIL ROMAN,CHAMOMILE OIL WILD, CHAMOMILE OIL WILD LOW LIMONENE, CINNAMON BARK OILCEYLAN, CISTE ABSOLUTE, CISTE ABSOLUTE COLORLESS, CITRONELLA OIL ASIAIRON FREE, CIVET ABS 75 PCT PG, CIVET ABSOLUTE, CIVET TINCTURE 10 PCT,CLARY SAGE ABS FRENCH DECOL, CLARY SAGE ABSOLUTE FRENCH, CLARY SAGEC′LESS 50 PCT PG, CLARY SAGE OIL FRENCH, COPAIBA BALSAM, COPAIBA BALSAMOIL, CORIANDER SEED OIL, CYPRESS OIL, CYPRESS OIL ORGANIC, DAVANA OIL,GALBANOL, GALBANUM ABSOLUTE COLORLESS, GALBANUM OIL, GALBANUM RESINOID,GALBANUM RESINOID 50 PCT DPG, GALBANUM RESINOID HERCOLYN BHT, GALBANUMRESINOID TEC BHT, GENTIANE ABSOLUTE MD 20 PCT BB, GENTIANE CONCRETE,GERANIUM ABS EGYPT MD, GERANIUM ABSOLUTE EGYPT, GERANIUM OIL CHINA,GERANIUM OIL EGYPT, GINGER OIL 624, GINGER OIL RECTIFIED SOLUBLE,GUAIACWOOD HEART, HAY ABS MD 50 PCT BB, HAY ABSOLUTE, HAY ABSOLUTE MD 50PCT TEC, HEALINGWOOD, HYSSOP OIL ORGANIC, IMMORTELLE ABS YUGO MD 50 PCTTEC, IMMORTELLE ABSOLUTE SPAIN, IMMORTELLE ABSOLUTE YUGO, JASMIN ABSINDIA MD, JASMIN ABSOLUTE EGYPT, JASMIN ABSOLUTE INDIA, ASMIN ABSOLUTEMOROCCO, JASMIN ABSOLUTE SAMBAC, JONQUILLE ABS MD 20 PCT BB, JONQUILLEABSOLUTE France, JUNIPER BERRY OIL FLG, JUNIPER BERRY OIL RECTIFIEDSOLUBLE, LABDANUM RESINOID 50 PCT TEC, LABDANUM RESINOID BB, LABDANUMRESINOID MD, LABDANUM RESINOID MD 50 PCT BB, LAVANDIN ABSOLUTE H,LAVANDIN ABSOLUTE MD, LAVANDIN OIL ABRIAL ORGANIC, LAVANDIN OIL GROSSOORGANIC, LAVANDIN OIL SUPER, LAVENDER ABSOLUTE H, LAVENDER ABSOLUTE MD,LAVENDER OIL COUMARIN FREE, LAVENDER OIL COUMARIN FREE ORGANIC, LAVENDEROIL MAILLETTE ORGANIC, LAVENDER OIL MT, MACE ABSOLUTE BB, MAGNOLIAFLOWER OIL LOW METHYL EUGENOL, MAGNOLIA FLOWER OIL, MAGNOLIA FLOWER OILMD, MAGNOLIA LEAF OIL, MANDARIN OIL MD, MANDARIN OIL MD BHT, MATEABSOLUTE BB, MOSS TREE ABSOLUTE MD TEX IFRA 43, MOSS-OAK ABS MD TEC IFRA43, MOSS-OAK ABSOLUTE IFRA 43, MOSS-TREE ABSOLUTE MD IPM IFRA 43, MYRRHRESINOID BB, MYRRH RESINOID MD, MYRRH RESINOID TEC, MYRTLE OIL IRONFREE, MYRTLE OIL TUNISIA RECTIFIED, NARCISSE ABS MD 20 PCT BB, NARCISSEABSOLUTE FRENCH, NEROLI OIL TUNISIA, NUTMEG OIL TERPENELESS, OEILLETABSOLUTE, OLIBANUM RESINOID, OLIBANUM RESINOID BB, OLIBANUM RESINOIDDPG, OLIBANUM RESINOID EXTRA 50 PCT DPG, OLIBANUM RESINOID MD, OLIBANUMRESINOID MD 50 PCT DPG, OLIBANUM RESINOID TEC, OPOPONAX RESINOID TEC,ORANGE BIGARADE OIL MD BHT, ORANGE BIGARADE OIL MD SCFC, ORANGE FLOWERABSOLUTE TUNISIA, ORANGE FLOWER WATER ABSOLUTE TUNISIA, ORANGE LEAFABSOLUTE, ORANGE LEAF WATER ABSOLUTE TUNISIA, ORRIS ABSOLUTE ITALY,ORRIS CONCRETE 15 PCT IRONE, ORRIS CONCRETE 8 PCT IRONE, ORRIS NATURAL15 PCT IRONE 4095C, ORRIS NATURAL 8 PCT IRONE 2942C, ORRIS RESINOID,OSMANTHUS ABSOLUTE, OSMANTHUS ABSOLUTE MD 50 PCT BB, PATCHOULI HEART N°3, PATCHOULI OIL INDONESIA, PATCHOULI OIL INDONESIA IRON FREE, PATCHOULIOIL INDONESIA MD, PATCHOULI OIL REDIST, PENNYROYAL HEART, PEPPERMINTABSOLUTE MD, PETITGRAIN BIGARADE OIL TUNISIA, PETITGRAIN CITRONNIER OIL,PETITGRAIN OIL PARAGUAY TERPENELESS, PETITGRAIN OIL TERPENELESS STAB,PIMENTO BERRY OIL, PIMENTO LEAF OIL, RHODINOL EX GERANIUM CHINA, ROSEABS BULGARIAN LOW METHYL EUGENOL, ROSE ABS MOROCCO LOW METHYL EUGENOL,ROSE ABS TURKISH LOW METHYL EUGENOL, ROSE ABSOLUTE, ROSE ABSOLUTEBULGARIAN, ROSE ABSOLUTE DAMASCENA, ROSE ABSOLUTE MD, ROSE ABSOLUTEMOROCCO, ROSE ABSOLUTE TURKISH, ROSE OIL BULGARIAN, ROSE OIL DAMASCENALOW METHYL EUGENOL, ROSE OIL TURKISH, ROSEMARY OIL CAMPHOR ORGANIC,ROSEMARY OIL TUNISIA, SANDALWOOD OIL INDIA, SANDALWOOD OIL INDIARECTIFIED, SANTALOL, SCHINUS MOLLE OIL, ST JOHN BREAD TINCTURE 10 PCT,STYRAX RESINOID, STYRAX RESINOID, TAGETE OIL, TEA TREE HEART, TONKA BEANABS 50 PCT SOLVENTS, TONKA BEAN ABSOLUTE, TUBEROSE ABSOLUTE INDIA,VETIVER HEART EXTRA, VETIVER OIL HAITI, VETIVER OIL HAITI MD, VETIVEROIL JAVA, VETIVER OIL JAVA MD, VIOLET LEAF ABSOLUTE EGYPT, VIOLET LEAFABSOLUTE EGYPT DECOL, VIOLET LEAF ABSOLUTE FRENCH, VIOLET LEAF ABSOLUTEMD 50 PCT BB, WORMWOOD OIL TERPENELESS, YLANG EXTRA OIL, YLANG III OILand combinations of these.

The colorants can be among those listed in the Color Index Internationalby the Society of Dyers and Colourists. Colorants include dyes andpigments and include those commonly used for coloring textiles, paints,inks and inkjet inks. Some colorants that can be utilized includecarotenoids, arylide yellows, diarylide yellows, β-naphthols, naphthols,benzimidazolones, disazo condensation pigments, pyrazolones, nickel azoyellow, phthalocyanines, quinacridones, perylenes and perinones,isoindolinone and isoindoline pigments, triarylcarbonium pigments,diketopyrrolo-pyrrole pigments, thioindigoids. Cartenoids include e.g.,alpha-carotene, beta-carotene, gamma-carotene, lycopene, lutein andastaxanthin Annatto extract, Dehydrated beets (beet powder),Canthaxanthin, Caramel, β-Apo-8′-carotenal, Cochineal extract, Carmine,Sodium copper chlorophyllin, Toasted partially defatted cookedcottonseed flour, Ferrous gluconate, Ferrous lactate, Grape colorextract, Grape skin extract (enocianina), Carrot oil, Paprika, Paprikaoleoresin, Mica-based pearlescent pigments, Riboflavin, Saffron,Titanium dioxide, carbon black, self-dispersed carbon, Tomato lycopeneextract; tomato lycopene concentrate, Turmeric, Turmeric oleoresin, FD&CBlue No. 1, FD&C Blue No. 2, FD&C Green No. 3, Orange B, Citrus Red No.2, FD&C Red No. 3, FD&C Red No. 40, FD&C Yellow No. 5, FD&C Yellow No.6, Alumina (dried aluminum hydroxide), Calcium carbonate, Potassiumsodium copper chlorophyllin (chlorophyllin-copper complex),Dihydroxyacetone, Bismuth oxychloride, Ferric ammonium ferrocyanide,Ferric ferrocyanide, Chromium hydroxide green, Chromium oxide greens,Guanine, Pyrophyllite, Talc, Aluminum powder, Bronze powder, Copperpowder, Zinc oxide, D&C Blue No. 4, D&C Green No. 5, D&C Green No. 6,D&C Green No. 8, D&C Orange No. 4, D&C Orange No. 5, D&C Orange No. 10,D&C Orange No. 11, FD&C Red No. 4, D&C Red No. 6, D&C Red No. 7, D&C RedNo. 17, D&C Red No. 21, D&C Red No. 22, D&C Red No. 27, D&C Red No. 28,D&C Red No. 30, D&C Red No. 31, D&C Red No. 33, D&C Red No. 34, D&C RedNo. 36, D&C Red No. 39, D&C Violet No. 2, D&C Yellow No. 7, Ext. D&CYellow No. 7, D&C Yellow No. 8, D&C Yellow No. 10, D&C Yellow No. 11,D&C Black No. 2, D&C Black No. 3 (3), D&C Brown No. 1, Ext. D&C,Chromium-cobalt-aluminum oxide, Ferric ammonium citrate, Pyrogallol,Logwood extract, 1,4-Bis[(2-hydroxy-ethyl)amino]-9,10-anthracenedionebis(2-propenoic)ester copolymers,1,4-Bis[(2-methylphenyl)amino]-9,10-anthracenedione,1,4-Bis[4-(2-methacryloxyethyl)phenylamino]anthraquinone copolymers,Carbazole violet, Chlorophyllin-copper complex, Chromium-cobalt-aluminumoxide, C.I. Vat Orange 1,2-[[2,5-Diethoxy-4-[(4-methylphenyl)thiol]phenyl]azo]-1,3,5-benzenetriol,16,23-Dihydrodinaphtho[2,3-a:2′,3′-i]naphth[2′,3′:6,7]indolo[2,3-c]carbazole-5,10,15,17,22,24-hexone,N,N′-(9,10-Dihydro-9,10-dioxo-1,5-anthracenediyl)bisbenzamide,7,16-Dichloro-6,15-dihydro-5,9,14,18-anthrazinetetrone,16,17-Dimethoxydinaphtho (1,2,3-cd:3′,2′,1′-lm) perylene-5,10-dione,Poly(hydroxyethyl methacrylate)-dye copolymers(3), Reactive Black 5,Reactive Blue 21, Reactive Orange 78, Reactive Yellow 15, Reactive BlueNo. 19, Reactive Blue No. 4, C.I. Reactive Red 11, C.I. Reactive Yellow86, C.I. Reactive Blue 163, C.I. Reactive Red 180,4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one(solvent Yellow 18),6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophen-3(2H)-one,Phthalocyanine green, Vinyl alcohol/methyl methacrylate-dye reactionproducts, C.I. Reactive Red 180, C.I. Reactive Black 5, C.I. ReactiveOrange 78, C.I. Reactive Yellow 15, C.I. Reactive Blue 21, Disodium1-amino-4-[[4-[(2-bromo-1-oxoallyl)amino]-2-sulphonatophenyl]amino]-9,10-dihydro-9,10-dioxoanthracene-2-sulphonate(Reactive Blue 69), D&C Blue No. 9, [Phthalocyaninato(2-)] copper andmixtures of these.

For example, a fragrance, e.g., natural wood fragrance, can becompounded into the resin used to make the composite. In someimplementations, the fragrance is compounded directly into the resin asan oil. For example, the oil can be compounded into the resin using aroll mill, e.g., a Banbury® mixer or an extruder, e.g., a twin-screwextruder with counter-rotating screws. An example of a Banbury® mixer isthe F-Series Banbury® mixer, manufactured by Farrel, Ansonia, Conn. Anexample of a twin-screw extruder is the WP ZSK 50 MEGACOMPOUNDER™,manufactured by Coperion, Stuttgart, Germany. After compounding, thescented resin can be added to the fibrous material and extruded ormolded. Alternatively, master batches of fragrance-filled resins areavailable commercially from International Flavors and Fragrances, underthe trade name POLYIFF™. In some embodiments, the amount of fragrance inthe composite is between about 0.005% by weight and about 10% by weight,e.g., between about 0.1% and about 5% or 0.25% and about 2.5%. Othernatural wood fragrances include evergreen or redwood. Other fragrancesinclude peppermint, cherry, strawberry, peach, lime, spearmint,cinnamon, anise, basil, bergamot, black pepper, camphor, chamomile,citronella, eucalyptus, pine, fir, geranium, ginger, grapefruit,jasmine, juniper berry, lavender, lemon, mandarin, marjoram, musk,myrrh, orange, patchouli, rose, rosemary, sage, sandalwood, tea tree,thyme, wintergreen, ylang ylang, vanilla, new car or mixtures of thesefragrances. In some embodiments, the amount of fragrance in the fibrousmaterial-fragrance combination is between about 0.005% by weight andabout 20% by weight, e.g., between about 0.1% and about 5% or 0.25% andabout 2.5%. Even other fragrances and methods are described U.S. Pat.No. 8,074,910 issued Dec. 13, 2011, the entire disclosure of whichincorporated herein by reference.

Uses of Poly Hydroxy-Carboxylic Acid and Poly Hydroxy-Carboxylic AcidCopolymers

Some uses of poly lactic acid and poly lactic acid containing materialsinclude: personal care items (e.g., tissues, towels, diapers), greenpackaging, garden (compostable pots), consumer electronics (e.g., laptopand mobile phone casings), appliances, food packaging, disposablepackaging (e.g., food containers and drink bottles), garbage bags (e.g.,waste compostable bags), mulch films, controlled release matrices andcontainers (e.g., for fertilizers, pesticides, herbicides, nutrients,pharmaceuticals, flavoring agents, foods), shopping bags, generalpurpose film, high heat film, heat seal layer, surface coating,disposable tableware (e.g., plates, cups, forks, knives, spoons, sporks,bowls), automotive parts (e.g., panels, fabrics, under hood covers),carpet fibers, clothing fibers (e.g., for garments, sportswear,footwear), biomedical applications (e.g., surgical sutures, implants,scaffolding, drug delivery systems, dialysis equipment) and engineeringplastics.

Other uses/industrial sectors that can benefit from the use of polylactic acid and poly lactic acid derivatives (e.g., elastomers) includeIT and software, Electronics, geoscience (e.g., oil and gas),engineering, aerospace (e.g., arm rests, seats, panels),telecommunications (e.g., headsets), chemical manufacturing,transportation such as automotive (e.g., dashboards, panels, tires,wheels), materials and steel, consumer packaged goods, wires and cables.

Other Advantages of Poly Hydroxy-Carboxylic Acid and PolyHydroxy-Carboxylic Acid Copolymers

Poly hydroxy-carboxylic acids are bio-based and can be composted,recycled, used as a fuel (incinerated). Some of the degradationreactions include thermal degradation, hydrolytic degradation and bioticdegradations.

For example, poly lactic acid can be thermally degraded. For example, athigh temperatures (e.g., between about 200-300° C., about 230-260° C.).The reactions involved in the thermal degradation of poly lactic acidcan follow different mechanisms such as thermo-hydrolysis, zipper-likedepolymerization (e.g., in the presence of residual catalysts),thermo-oxidative degradation. Trans-esterification reactions can alsooperate on the polymer causing bond breaking and/or bond making.

Poly hydroxy-carboxylic acid also can undergo hydrolytic degradation.Hydrolytic degradation includes chain scission producing shorterpolymers, oligomers and eventually the monomer, hydroxylic-carboxylicacid can be released. Hydrolysis can be associated with thermal andbiotic degradation. For the example of poly lactic acid, the process canbe effected by various parameters such as the poly lactic acidstructure, its molecular weight and distribution, its morphology (e.g.,crystallinity), the shape of the sample (e.g., isolated thin samples orcomminuted samples can degrade faster), the thermal and mechanicalhistory (e.g., processing) and the hydrolysis conditions (e.g.,temperature, agitation, comminution). The hydrolysis of poly lactic acidstarts with a water uptake phase, followed by hydrolytic splitting ofthe ester bonds. The amorphous parts of the polyesters can be hydrolyzedfaster than the crystalline regions because of the higher water uptakeand mobility of chain segments in these regions. In a second stage, thecrystalline regions of poly lactic acid are hydrolyzed.

Poly hydroxy-carboxylic acid can also undergo biotic degradation. Thisdegradation can occur for example, in a mammalian body, and has usefulimplications for degradable stitching and can have detrimentalimplications to other surgical implants. Enzymes, such as proteinase Kand pronase can be utilized.

During composting, poly hydroxy-carboxylic acid can go through severaldegradation stages. For example, an initial stage can occur due toexposure to moisture wherein the degradation is abiotic and the polyhydroxy-carboxylic acid degrades by hydrolysis. This stage can beaccelerated by the presence of acids and bases and elevatedtemperatures. The first stage can lead to embrittlement of the polymerwhich can facilitate the diffusion of poly hydroxy-carboxylic acid outof the bulk polymers. The oligomers can then be attacked bymicro-organisms. Organisms can degrade the oligomers and D-lactic acidand/or L-lactic acid, leading to CO₂ and water. Time for thisdegradation is on the order of about one to a few years depending on thefactors previously mentioned. The degradation time is several orders ofmagnitude faster than typical petroleum based plastic such aspolyethylene (e.g., on the order of hundreds of years).

Poly hydroxy-carboxylic acid may be recycled. For example, the polylactic acid can be hydrolyzed to D-lactic acid and/or L-lactic acid,purified and re-polymerized. Unlike other recyclable plastics such aspolyethylene terephthalate and high density polyethylene, PLA polylactic acid does not need to be down-graded to make a product ofdiminished value (e.g., from a bottle to decking or carpet). Poly lacticacid can be in theory recycled indefinitely. Optionally, poly lacticacid can be re-used and downgraded for several generations and thenconverted to lactic acid and re-polymerized.

Poly hydroxy-carboxylic acid can also be used as a fuel, for example,for energy production. Poly lactic acid can have high heat content e.g.,up to about 8400 BTU. Incineration of pure poly lactic acid onlyreleases carbon dioxide and water. Combinations with other ingredientstypically amount to less than 1 ppm of non poly lactic acid residuals(e.g., ash). Thus the combustion of poly lactic acid is cleaner thanother renewable fuels, e.g. wood.

Poly hydroxy-carboxylic acid can have high gloss, high transparency,high clarity, high stiffness, can be UV stable, Non-allergenic, highflavor and aroma barrier properties, easy to blend, easy to mold, easyto shape, easy to emboss, easy to print on, lightweight, compostable.

Poly hydroxy-carboxylic acid can also be printed on for example, bylithographic, ink-jet printing, laser printing, fixed type printing,roller printing. Some poly hydroxy-carboxylic acid can also be writtenon, for example, using a pen.

Processing as described herein can also include irradiation. Forexample, irradiation with between about 1 and 150 Mrad radiation (e.g.,for example, any range as described herein) can improve thecompostability and recyclability of poly hydroxy-carboxylic acid andpoly hydroxy-carboxylic acid containing materials.

Addition of Catalyst Deactivating Agent and Similar Additives

The polymerization of hydroxy-carboxylic acids is most often done with acatalyst. This catalyst can persist in the final polymer product and assuch can be able to catalyze a reverse reaction when water is present,or possibly other deleterious chemistries. The catalyst can bedeactivated by addition of deactivating agents such as anhydrides,phosphite, antioxidants or multifunctional carboxylic acids. The mosteffective multifunctional carboxylic acids are those where twocarboxylic acids are not more than about six carbon atoms apart whereinthen counted carbon atoms include the carbonyl carbon. Examples ofpolycarboxylic acids include dicarboxylic acids such as tartaric acid,succinic acid, malic acid, fumaric acid, and adipic acid and whereappropriate the stereoisomers. Another type of multifunctionalcarboxylic acid includes polycarboxylic acid which includes oligomersand polymers containing three or more carboxylic acid groups and amolecular weight of greater than about 500. A particularly preferredpolycarboxylic acids includes polyacrylic acid. Without being bound bytheory, the carboxylic acids near to each may be such that they canchelate the catalyst and leave it in a state where its catalytic siteshave been occupied, thus reducing the negative reactions.

Polymers of poly carboxylic acid can include polyacrylic acids andespecially poly(meth)acrylic acids. The latter has the advantage that itmay render the complexed catalyst more soluble in the polymer. It shouldbe noted that the poly(meth)acrylic and poly acrylic acids must beincluded as discreet polymers and not as the (meth)acrylic acid. Thesepoly(meth)acrylic acids have pendant carboxylic acids, not carboxylicacids that become part of the polyester chain.

Phosphite antioxidants include Tris(2,4-ditert-butylphenyl)phosphite andother tri substituted phosphites. These may also be used to deactivatethe catalysts.

Compounds like ethylenediaminetetraacetic acid, commonly abbreviated asEDTA may also be used to complex with and/or deactivate the catalyst.Compounds related to EDTA may also be used, such asN-(hydroxyethyl)-ethylenediamine-triacetic acid, diethylene triaminepentaacetic acid, and nitrilotriacetic acid.

Anhydrides include acetic anhydride, pivaloyl anhydride, maleicanhydride, succinic anhydride. When anhydrides are used 2 to 60 molarequivalents based on the moles of catalysts can be used.

These additives for the poly hydroxy-carboxylic acids can easily beadded just prior, during or directly after the polymer is processed inthe thin film evaporator or thin film polymerization/devolatilizationdevice. They can be described as stabilizers.

Compounds that are solids are also candidates to deactivate thecatalysts. Not only can these bind/bond to the catalyst they can be ofsuch a size that the filtration of the catalyst from the polymer isimproved. These include hydroxylic medium, and similar compounds.

Combinations of these additives may also be used. For instanceanhydrides may be used with the solids may be used. For example, aceticanhydride and alumina may be used to deactivate the catalyst andfacilitate removal by filtration.

The catalyst may be removed after complexation/reactionwith/binding/bonding to the catalysts deactivating systems describedabove. The removal can be just prior to/during/after the thin filmevaporator system described above.

Radiation Treatment

The feedstock (e.g., cellulosic, lignocellulosic, and combinations ofthese) that can produce precursors to hydroxy-carboxylic acids can betreated with electron bombardment to modify its structure, for example,to reduce its recalcitrance or cross link the structures. Such treatmentcan, for example, reduce the average molecular weight of the feedstock,change the crystalline structure of the feedstock, and/or increase thesurface area and/or porosity of the feedstock. Radiation can be by, forexample, electron beam, ion beam, 100 nm to 28 nm ultraviolet (UV)light, gamma or X-ray radiation. Radiation treatments and systems fortreatments are discussed in U.S. Pat. No. 8,142,620, and U.S. patentapplication Ser. No. 12/417,731, the entire disclosures of which areincorporated herein by reference.

Each form of radiation ionizes the biomass via particular interactions,as determined by the energy of the radiation. Heavy charged particlesprimarily ionize matter via Coulomb scattering; furthermore, theseinteractions produce energetic electrons that may further ionize matter.Alpha particles are identical to the nucleus of a helium atom and areproduced by the alpha decay of various radioactive nuclei, such asisotopes of bismuth, polonium, astatine, radon, francium, radium,several actinides, such as actinium, thorium, uranium, neptunium,curium, californium, americium, and plutonium. Electrons interact viaCoulomb scattering and bremsstrahlung radiation produced by changes inthe velocity of electrons.

When particles are utilized, they can be neutral (uncharged), positivelycharged or negatively charged. When charged, the charged particles canbear a single positive or negative charge, or multiple charges, e.g.,one, two, three or even four or more charges. In instances in whichchain scission is desired to change the molecular structure of thecarbohydrate containing material, positively charged particles may bedesirable, in part, due to their acidic nature. When particles areutilized, the particles can have the mass of a resting electron, orgreater, e.g., 500, 1000, 1500, or 2000 or more times the mass of aresting electron. For example, the particles can have a mass of fromabout 1 atomic unit to about 150 atomic units, e.g., from about 1 atomicunit to about 50 atomic units, or from about 1 to about 25, e.g., 1, 2,3, 4, 5, 10, 12 or 15 atomic units.

Gamma radiation has the advantage of a significant penetration depthinto a variety of material in the sample. In embodiments in which theirradiating is performed with electromagnetic radiation, theelectromagnetic radiation can have, e.g., energy per photon (in electronvolts) of greater than 10² eV, e.g., greater than 10³, 10⁴, 10⁵, 10⁶, oreven greater than 10⁷ eV. In some embodiments, the electromagneticradiation has energy per photon of between 10⁴ and 10⁷, e.g., between10⁵ and 10⁶ eV. The electromagnetic radiation can have a frequency of,e.g., greater than 10¹⁶ Hz, greater than 10 ¹⁷ Hz, 10¹⁸, 10¹⁹, 10²⁰, oreven greater than 10²¹ Hz. In some embodiments, the electromagneticradiation has a frequency of between 10¹⁸ and 10²² Hz, e.g., between10¹⁹ to 10²¹ Hz.

Electron bombardment may be performed using an electron beam device thathas a nominal energy of less than 10 MeV, e.g., less than 7 MeV, lessthan 5 MeV, or less than 2 MeV, e.g., from about 0.5 to 1.5 MeV, fromabout 0.8 to 1.8 MeV, or from about 0.7 to 1 MeV. In someimplementations the nominal energy is about 500 to 800 keV.

The electron beam may have a relatively high total beam power (thecombined beam power of all accelerating heads, or, if multipleaccelerators are used, of all accelerators and all heads), e.g., atleast 25 kW, e.g., at least 30, 40, 50, 60, 65, 70, 80, 100, 125, or150, 250, 300 kW. In some cases, the power is even as high as 500 kW,750 kW, or even 1000 kW or more. In some cases the electron beam has abeam power of 1200 kW or more, e.g., 1400, 1600, 1800, or even 3000 kW.The electron beam may have a total beam power of 25 to 3000 kW.Alternatively, the electron beam may have a total beam power of 75 to1500 kW. Optionally, the electron beam may have a total beam power of100 to 1000 kW. Alternatively, the electron beam may have a total beampower of 100 to 400 kW.

This high total beam power is usually achieved by utilizing multipleaccelerating heads. For example, the electron beam device may includetwo, four, or more accelerating heads. The use of multiple heads, eachof which has a relatively low beam power, prevents excessive temperaturerise in the material, thereby preventing burning of the material, andalso increases the uniformity of the dose through the thickness of thelayer of material.

It is generally preferred that the bed of biomass material has arelatively uniform thickness. In some embodiments the thickness is lessthan about 1 inch (e.g., less than about 0.75 inches, less than about0.5 inches, less than about 0.25 inches, less than about 0.1 inches,between about 0.1 and 1 inch, between about 0.2 and 0.3 inches).

It is desirable to treat the material as quickly as possible. Ingeneral, it is preferred that treatment be performed at a dose rate ofgreater than about 0.25 Mrad per second, e.g., greater than about 0.5,0.75, 1, 1.5, 2, 5, 7, 10, 12, 15, or even greater than about 20 Mradper second, e.g., about 0.25 to 30 Mrad per second. Alternately, thetreatment is performed at a dose rate of 0.5 to 20 Mrad per second.Optionally, the treatment is performed at a dose rate of 0.75 to 15 Mradper second. Alternately, the treatment is performed at a dose rate of 1to 5 Mrad per second. Optionally, the treatment is performed at a doserate of 1-3 Mrad per second or alternatively 1-2 Mrad per second. Higherdose rates allow a higher throughput for a target (e.g., the desired)dose. Higher dose rates generally require higher line speeds, to avoidthermal decomposition of the material. In one implementation, theaccelerator is set for 3 MeV, 50 mA beam current, and the line speed is24 feet/minute, for a sample thickness of about 20 mm (e g , comminutedcorn cob material with a bulk density of 0.5 g/cm³).

In some embodiments, electron bombardment is performed until thematerial receives a total dose of at least 0.1 Mrad, 0.25 Mrad, 1 Mrad,5 Mrad, e.g., at least 10, 20, 30 or at least 40 Mrad. In someembodiments, the treatment is performed until the material receives adose of from about 10 Mrad to about 50 Mrad, e.g., from about 20 Mrad toabout 40 Mrad, or from about 25 Mrad to about 30 Mrad. In someimplementations, a total dose of 25 to 35 Mrad is preferred, appliedideally over a couple of passes, e.g., at 5 Mrad/pass with each passbeing applied for about one second. Cooling methods, systems andequipment can be used before, during, after and in between radiations,for example, utilizing a cooling screw conveyor and/or a cooledvibratory conveyor.

Using multiple heads as discussed above, the material can be treated inmultiple passes, for example, two passes at 10 to 20 Mrad/pass, e.g., 12to 18 Mrad/pass, separated by a few seconds of cool-down, or threepasses of 7 to 12 Mrad/pass, e.g., 5 to 20 Mrad/pass, 10 to 40Mrad/pass, 9 to 11 Mrad/pass. As discussed herein, treating the materialwith several relatively low doses, rather than one high dose, tends toprevent overheating of the material and also increases dose uniformitythrough the thickness of the material. In some implementations, thematerial is stirred or otherwise mixed during or after each pass andthen smoothed into a uniform layer again before the next pass, tofurther enhance treatment uniformity.

In some embodiments, electrons are accelerated to, for example, a speedof greater than 75 percent of the speed of light, e.g., greater than 85,90, 95, or 99 percent of the speed of light.

In some embodiments, any processing described herein occurs onlignocellulosic material that remains dry as acquired or that has beendried, e.g., using heat and/or reduced pressure. For example, in someembodiments, the cellulosic and/or lignocellulosic material has lessthan about 25 wt. % retained water, measured at 25° C. and at fiftypercent relative humidity (e.g., less than about 20 wt. %, less thanabout 15 wt. %, less than about 14 wt. %, less than about 13 wt. %, lessthan about 12 wt. %, less than about 10 wt. %, less than about 9 wt. %,less than about 8 wt. %, less than about 7 wt. %, less than about 6 wt.%, less than about 5 wt. %, less than about 4 wt. %, less than about 3wt. %, less than about 2 wt. %, less than about 1 wt. %, or less thanabout 0.5 wt. %.

In some embodiments, two or more ionizing sources can be used, such astwo or more electron sources. For example, samples can be treated, inany order, with a beam of electrons, followed by gamma radiation and UVlight having wavelengths from about 100 nm to about 280 nm In someembodiments, samples are treated with three ionizing radiation sources,such as a beam of electrons, gamma radiation, and energetic UV light.The biomass is conveyed through the treatment zone where it can bebombarded with electrons.

It may be advantageous to repeat the treatment to more thoroughly reducethe recalcitrance of the biomass and/or further modify the biomass. Inparticular. the process parameters can be adjusted after a first (e.g.,second, third, fourth or more) pass depending on the recalcitrance ofthe material. In some embodiments, a conveyor can be used which includesa circular system where the biomass is conveyed multiple times throughthe various processes described above. In some other embodiments,multiple treatment devices (e.g., electron beam generators) are used totreat the biomass multiple (e.g., 2, 3, 4 or more) times. In yet otherembodiments, a single electron beam generator may be the source ofmultiple beams (e.g., 2, 3, 4 or more beams) that can be used fortreatment of the biomass.

The effectiveness in changing the molecular/supermolecular structureand/or reducing the recalcitrance of the carbohydrate-containing biomassdepends on the electron energy used and the dose applied, while exposuretime depends on the power and dose. In some embodiments, the dose rateand total dose are adjusted so as not to destroy (e.g., char or burn)the biomass material. For example, the carbohydrates should not bedamaged in the processing so that they can be released from the biomassintact, e.g. as monomeric sugars.

In some embodiments, the treatment (with any electron source or acombination of sources) is performed until the material receives a doseof at least about 0.05 Mrad, e.g., at least about 0.1, 0.25, 0.5, 0.75,1.0, 2.5, 5.0, 7.5, 10.0, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100,125, 150, 175, or 200 Mrad. In some embodiments, the treatment isperformed until the material receives a dose of between 0.1-100 Mrad,1-200, 5-200, 10-200, 5-150, 50-150 Mrad, 5-100, 5-50, 5-40, 10-50,10-75, 15-50, 20-35 Mrad.

In some embodiments, relatively low doses of radiation are utilized,e.g., to increase the molecular weight of a cellulosic orlignocellulosic material (with any radiation source or a combination ofsources described herein). For example, a dose of at least about 0.05Mrad, e.g., at least about 0.1 Mrad or at least about 0.25, 0.5, 0.75.1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or at least about 5.0 Mrad. In someembodiments, the irradiation is performed until the material receives adose of between 0.1Mrad and 2.0 Mrad, e.g., between 0.5rad and 4.0 Mrador between 1.0 Mrad and 3.0 Mrad.

It also can be desirable to irradiate from multiple directions,simultaneously or sequentially, in order to achieve a desired degree ofpenetration of radiation into the material. For example, depending onthe density and moisture content of the material, such as wood, and thetype of radiation source used (e.g., gamma or electron beam), themaximum penetration of radiation into the material may be only about0.75 inch. In such a cases, a thicker section (up to 1.5 inch) can beirradiated by first irradiating the material from one side, and thenturning the material over and irradiating from the other side.Irradiation from multiple directions can be particularly useful withelectron beam radiation, which irradiates faster than gamma radiationbut typically does not achieve as great a penetration depth.

Radiation Sources

The type of radiation determines the kinds of radiation sources used aswell as the radiation devices and associated equipment. The methods,systems and equipment described herein, for example, for treatingmaterials with radiation, can utilized sources as described herein aswell as any other useful source.

Sources of gamma rays include radioactive nuclei, such as isotopes ofcobalt, calcium, technetium, chromium, gallium, indium, iodine, iron,krypton, samarium, selenium, sodium, thallium, and xenon.

Sources of X-rays include electron beam collision with metal targets,such as tungsten or molybdenum or alloys, or compact light sources, suchas those produced commercially by Lyncean.

Alpha particles are identical to the nucleus of a helium atom and areproduced by the alpha decay of various radioactive nuclei, such asisotopes of bismuth, polonium, astatine, radon, francium, radium,several actinides, such as actinium, thorium, uranium, neptunium,curium, californium, americium, and plutonium.

Sources for ultraviolet radiation include deuterium or cadmium lamps.

Sources for infrared radiation include sapphire, zinc, or selenidewindow ceramic lamps.

Sources for microwaves include klystrons, Slevin type RF sources, oratom beam sources that employ hydrogen, oxygen, or nitrogen gases.

Accelerators used to accelerate the particles can be electrostatic DC,electrodynamic DC, RF linear, magnetic induction linear or continuouswave. For example, cyclotron type accelerators are available from IBA,Belgium, such as the RHODOTRON™ system, while DC type accelerators areavailable from RDI, now IBA Industrial, such as the DYNAMITRON®. Ionsand ion accelerators are discussed in Introductory Nuclear Physics,Kenneth S. Krane, John Wiley & Sons, Inc. (1988), Krsto Prelec, FIZIKA B6 (1997) 4, 177-206, Chu, William T., “Overview of Light-Ion BeamTherapy”, Columbus-Ohio, ICRU-IAEA Meeting, 18-20 Mar. 2006, Iwata, Y.et al., “Alternating-Phase-Focused IH-DTL for Heavy-Ion MedicalAccelerators”, Proceedings of EPAC 2006, Edinburgh, Scotland, andLeitner, C. M. et al., “Status of the Superconducting ECR Ion SourceVenus”, Proceedings of EPAC 2000, Vienna, Austria

Electrons may be produced by radioactive nuclei that undergo beta decay,such as isotopes of iodine, cesium, technetium, and iridium.Alternatively, an electron gun can be used as an electron source viathermionic emission and accelerated through an accelerating potential.An electron gun generates electrons, which are then accelerated througha large potential (e.g., greater than about 500 thousand, greater thanabout 1 million, greater than about 2 million, greater than about 5million, greater than about 6 million, greater than about 7 million,greater than about 8 million, greater than about 9 million, or evengreater than 10 million volts) and then scanned magnetically in the x-yplane, where the electrons are initially accelerated in the z directiondown the accelerator tube and extracted through a foil window. Scanningthe electron beams is useful for increasing the irradiation surface whenirradiating materials, e.g., a biomass, that is conveyed through thescanned beam. Scanning the electron beam also distributes the thermalload homogenously on the window and helps reduce the foil window rupturedue to local heating by the electron beam. Window foil rupture is acause of significant down-time due to subsequent necessary repairs andre-starting the electron gun.

Various other irradiating devices may be used in the methods disclosedherein, including field ionization sources, electrostatic ionseparators, field ionization generators, thermionic emission sources,microwave discharge ion sources, recirculating or static accelerators,dynamic linear accelerators, van de Graaff accelerators, and foldedtandem accelerators. Such devices are disclosed, for example, in U.S.Pat. No. 7,931,784 to Medoff, the complete disclosure of which isincorporated herein by reference.

A beam of electrons can be used as the radiation source. A beam ofelectrons has the advantages of high dose rates (e.g., 1, 5, or even 10Mrad per second), high throughput, less containment, and lessconfinement equipment. Electron beams can also have high electricalefficiency (e.g., 80%), allowing for lower energy usage relative toother radiation methods, which can translate into a lower cost ofoperation and lower greenhouse gas emissions corresponding to thesmaller amount of energy used. Electron beams can be generated, e.g., byelectrostatic generators, cascade generators, transformer generators,low energy accelerators with a scanning system, low energy acceleratorswith a linear cathode, linear accelerators, and pulsed accelerators.

Electrons can also be more efficient at causing changes in the molecularstructure of carbohydrate-containing materials, for example, by themechanism of chain scission. In addition, electrons having energies of0.5-10 MeV can penetrate low density materials, such as the biomassmaterials described herein, e.g., materials having a bulk density ofless than 0.5 g/cm³, and a depth of 0.3-10 cm. Electrons as an ionizingradiation source can be useful, e.g., for relatively thin piles, layersor beds of materials, e.g., less than about 0.5 inch, e.g., less thanabout 0.4 inch, 0.3 inch, 0.25 inch, or less than about 0.1 inch. Insome embodiments, the energy of each electron of the electron beam isfrom about 0.3 MeV to about 2.0 MeV (million electron volts), e.g., fromabout 0.5 MeV to about 1.5 MeV, or from about 0.7 MeV to about 1.25 MeV.Methods of irradiating materials are discussed in U.S. Pat. App. Pub.2012/0100577 A1, filed Oct. 18, 2011, the entire disclosure of which isherein incorporated by reference.

Electron beam irradiation devices may be procured commercially from IonBeam Applications, Louvain-la-Neuve, Belgium, NHV Corporation, Japan orthe Titan Corporation, San Diego, Calif. Typical electron energies canbe 0.5 MeV, 1 MeV, 2 MeV, 4.5 MeV, 7.5 MeV, or 10 MeV. Typical electronbeam irradiation device power can be 1 kW, 5 kW, 10 kW, 20 kW, 50 kW, 60kW, 70 kW, 80 kW, 90 kW, 100 kW, 125 kW, 150 kW, 175 kW, 200 kW, 250 kW,300 kW, 350 kW, 400 kW, 450 kW, 500 kW, 600 kW, 700 kW, 800 kW, 900 kWor even 1000 kW.

Tradeoffs in considering electron beam irradiation device powerspecifications include cost to operate, capital costs, depreciation, anddevice footprint. Tradeoffs in considering exposure dose levels ofelectron beam irradiation would be energy costs and environment, safety,and health (ESH) concerns. Typically, generators are housed in a vault,e.g. , of lead or concrete, especially for production from X-rays thatare generated in the process. Tradeoffs in considering electron energiesinclude energy costs.

The electron beam irradiation device can produce either a fixed beam ora scanning beam. A scanning beam may be advantageous with large scansweep length and high scan speeds, as this would effectively replace alarge, fixed beam width. Further, available sweep widths of 0.5 m, 1 m,2 m or more are available. The scanning beam is preferred in mostembodiments describe herein because of the larger scan width and reducedpossibility of local heating and failure of the windows.

Electron Guns—Windows

The extraction system for an electron accelerator can include two windowfoils. The cooling gas in the two foil window extraction system can be apurge gas or a mixture, for example, air, or a pure gas. In oneembodiment the gas is an inert gas such as nitrogen, argon, helium andor carbon dioxide. It is preferred to use a gas rather than a liquidsince energy losses to the electron beam are minimized Mixtures of puregas can also be used, either pre-mixed or mixed in line prior toimpinging on the windows or in the space between the windows. Thecooling gas can be cooled, for example, by using a heat exchange system(e.g., a chiller) and/or by using boil off from a condensed gas (e.g.,liquid nitrogen, liquid helium). Window foils are described inPCT/US2013/64332 filed Oct. 10, 2013 the full disclosure of which isincorporated by reference herein.

Electron Guns—Beam Stops

In some embodiments the systems and methods include a beam stop (e.g., ashutter). For example, the beam stop can be used to quickly stop orreduce the irradiation of material without powering down the electronbeam device. Alternatively the beam stop can be used while powering upthe electron beam, e.g., the beam stop can stop the electron beam untila beam current of a desired level is achieved. The beam stop can beplaced between the primary foil window and a secondary foil window. Forexample, the beam stop can be mounted so that it is movable, that is, sothat it can be moved into and out of the beam path. Even partialcoverage of the beam can be used, for example, to control the dose ofirradiation. The beam stop can be mounted to the floor, to a conveyorfor the biomass, to a wall, to the radiation device (e.g., at the scanhorn), or to any structural support. Preferably the beam stop is fixedin relation to the scan horn so that the beam can be effectivelycontrolled by the beam stop. The beam stop can incorporate a hinge, arail, wheels, slots, or other means allowing for its operation in movinginto and out of the beam. The beam stop can be made of any material thatwill stop at least 5% of the electrons, e.g., at least 10%, 20%, 30%,40%, 50%, 60%, 70%, at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99% or even about 100% of the electrons.

The beam stop can be made of a metal including, but not limited to,stainless steel, lead, iron, molybdenum, silver, gold, titanium,aluminum, tin, or alloys of these, or laminates (layered materials) madewith such metals (e.g., metal-coated ceramic, metal-coated polymer,metal-coated composite, multilayered metal materials).

The beam stop can be cooled, for example, with a cooling fluid such asan aqueous solution or a gas. The beam stop can be partially orcompletely hollow, for example, with cavities. Interior spaces of thebeam stop can be used for cooling fluids and gases. The beam stop can beof any shape, including flat, curved, round, oval, square, rectangular,beveled and wedged shapes.

The beam stop can have perforations so as to allow some electronsthrough, thus controlling (e.g., reducing) the levels of radiationacross the whole area of the window, or in specific regions of thewindow. The beam stop can be a mesh formed, for example, from fibers orwires. Multiple beam stops can be used, together or independently, tocontrol the irradiation. The beam stop can be remotely controlled, e.g.,by radio signal or hard wired to a motor for moving the beam into or outof position.

Beam Dumps

The embodiments disclosed herein can also include a beam dump whenutilizing a radiation treatment. A beam dump's purpose is to safelyabsorb a beam of charged particles. Like a beam stop, a beam dump can beused to block the beam of charged particles. However, a beam dump ismuch more robust than a beam stop, and is intended to block the fullpower of the electron beam for an extended period of time. They areoften used to block the beam as the accelerator is powering up.

Beam dumps are also designed to accommodate the heat generated by suchbeams, and are usually made from materials such as copper, aluminum,carbon, beryllium, tungsten, or mercury. Beam dumps can be cooled, forexample, using a cooling fluid that can be in thermal contact with thebeam dump.

Heating and Throughput During Radiation Treatment

Several processes can occur in biomass when electrons from an electronbeam interact with matter in inelastic collisions. For example,ionization of the material, chain scission of polymers in the material,cross linking of polymers in the material, oxidation of the material,generation of X-rays (“Bremsstrahlung”) and vibrational excitation ofmolecules (e.g., phonon generation). Without being bound to a particularmechanism, the reduction in recalcitrance can be due to several of theseinelastic collision effects, for example, ionization, chain scission ofpolymers, oxidation and phonon generation. Some of the effects (e.g.,especially X-ray generation), necessitate shielding and engineeringbarriers, for example, enclosing the irradiation processes in a concrete(or other radiation opaque material) vault. Another effect ofirradiation, vibrational excitation, is equivalent to heating up thesample. Heating the sample by irradiation can help in recalcitrancereduction, but excessive heating can destroy the material, as will beexplained below.

The adiabatic temperature rise (ΔT) from adsorption of ionizingradiation is given by the equation: ΔT=D/Cp : where D is the averagedose in kGy, C_(p) is the heat capacity in J/g° C., and ΔT is the changein temperature in degrees Celsius. A typical dry biomass material willhave a heat capacity close to 2. Wet biomass will have a higher heatcapacity dependent on the amount of water since the heat capacity ofwater is very high (4.19 J/g° C.). Metals have much lower heatcapacities, for example, 304 stainless steel has a heat capacity of 0.5J/g° C. The estimated temperature change due to the instant adsorptionof radiation in a biomass and stainless steel for various doses ofradiation is shown in Table 1.

TABLE 1 Calculated Temperature increase for biomass and stainless steel.Dose Estimated Biomass Steel (Mrad) ΔT (° C.) ΔT (° C.) 10 50 200 50250, decomposition 1000 100 500, decomposition 2000 150 750,decomposition 3000 200 1000, decomposition.  4000

High temperatures can destroy and or modify the biopolymers in biomassso that the polymers (e.g., cellulose) are unsuitable for furtherprocessing. A biomass subjected to high temperatures can become dark,sticky and give off odors indicating decomposition. The stickiness caneven make the material hard to convey. The odors can be unpleasant andbe a safety issue. In fact, keeping the biomass below about 200° C. hasbeen found to be beneficial in the processes described herein (e.g.,below about 190° C., below about 180° C., below about 170° C., belowabout 160° C., below about 150° C., below about 140° C., below about130° C., below about 120° C., below about 110° C., between about 60° C.and 180° C., between about 60° C. and 160° C., between about 60° C. and150° C., between about 60° C. and 140° C., between about 60° C. and 130°C., between about 60° C. and 120° C., between about 80° C. and 180° C.,between about 100° C. and 180° C., between about 120° C. and 180° C.,between about 140° C. and 180° C., between about 160° C. and 180° C.,between about 100° C. and 140° C., between about 80° C. and 120° C.).

It has been found that irradiation above about 10 Mrad is desirable forthe processes described herein (e.g., reduction of recalcitrance). Ahigh throughput is also desirable so that the irradiation does notbecome a bottle neck in processing the biomass. The treatment isgoverned by a Dose rate equation: M=FP/D·time, where M is the mass ofirradiated material (kg), F is the fraction of power that is adsorbed(unit less), P is the emitted power (kW=Voltage in MeV×Current in mA),time is the treatment time (sec) and D is the adsorbed dose (kGy). In anexemplary process where the fraction of adsorbed power is fixed, thePower emitted is constant and a set dosage is desired, the throughput(e.g., M, the biomass processed) can be increased by increasing theirradiation time. However, increasing the irradiation time withoutallowing the material to cool, can excessively heat the material asexemplified by the calculations shown above. Since biomass has a lowthermal conductivity (less than about 0.1 Wm⁻¹K⁻¹), heat dissipation isslow, unlike, for example, metals (greater than about 10 Wm⁻¹K⁻¹) whichcan dissipate energy quickly as long as there is a heat sink to transferthe energy to.

Biomass Materials

Lignocellulosic materials include, but are not limited to, wood (e.g.,softwood, Pine softwood, Softwood, Softwood barks, Softwood stems,Spruce softwood, Hardwood, Willow Hardwood, aspen hardwood, BirchHardwood, Hardwood barks, Hardwood stems, pine cones, pine needles),particle board, chemical pulps, mechanical pulps, paper, waste paper,forestry wastes (e.g., sawdust, aspen wood, wood chips, leaves),grasses, (e.g., switchgrass, miscanthus, cord grass, reed canary grass,coastal Bermuda grass), grain residues, (e.g., rice hulls, oat hulls,wheat chaff, barley hulls), agricultural waste (e.g., silage, canolastraw, wheat straw, barley straw, oat straw, rice straw, jute, hemp,flax, bamboo, sisal, abaca, corn cobs, corn stover, soybean stover, cornfiber, alfalfa, hay, coconut hair, nut shells, palm and coconut oilbyproducts), cotton, cotton seed hairs, flax, sugar processing residues(e.g., bagasse, beet pulp, agave bagasse), algae, seaweed, manure (e.g.,Solid cattle manure, Swine waste), sewage, carrot processing waste,molasses spent wash, alfalfa biver and mixtures of any of these.

In some cases, the lignocellulosic material includes corncobs. Ground orhammermilled corncobs can be spread in a layer of relatively uniformthickness for irradiation, and after irradiation are easy to disperse inthe medium for further processing. To facilitate harvest and collection,in some cases the entire corn plant is used, including the corn stalk,corn kernels, and in some cases even the root system of the plant.

Advantageously, no additional nutrients (other than a nitrogen source,e.g., urea or ammonia) are required during fermentation of corncobs orcellulosic or lignocellulosic materials containing significant amountsof corncobs.

Corncobs, before and after comminution, are also easier to convey anddisperse, and have a lesser tendency to form explosive mixtures in airthan other cellulosic or lignocellulosic materials such as hay andgrasses.

Cellulosic materials include, for example, paper, paper products, paperwaste, paper pulp, pigmented papers, loaded papers, coated papers,filled papers, magazines, printed matter (e.g., books, catalogs,manuals, labels, calendars, greeting cards, brochures, prospectuses,newsprint), printer paper, polycoated paper, card stock, cardboard,paperboard, materials having a high α-cellulose content such as cotton,and mixtures of any of these. for example, paper products as describedin U.S. application Ser. No. 13/396,365 (“Magazine Feedstocks” by Medoffet al., filed Feb. 14, 2012), the full disclosure of which isincorporated herein by reference.

Cellulosic materials can also include lignocellulosic materials whichhave been partially or fully de-lignified.

In some instances other biomass materials can be utilized, for example,starchy materials. Starchy materials include starch itself, e.g., cornstarch, wheat starch, potato starch or rice starch, a derivative ofstarch, or a material that includes starch, such as an edible foodproduct or a crop. For example, the starchy material can be arracacha,buckwheat, banana, barley, cassava, kudzu, oca, sago, sorghum, regularhousehold potatoes, sweet potato, taro, yams, or one or more beans, suchas favas, lentils or peas. Blends of any two or more starchy materialsare also starchy materials. Mixtures of starchy, cellulosic and orlignocellulosic materials can also be used. For example, a biomass canbe an entire plant, a part of a plant or different parts of a plant,e.g., a wheat plant, cotton plant, a corn plant, rice plant or a tree.The starchy materials can be treated by any of the methods describedherein.

Microbial materials include, but are not limited to, any naturallyoccurring or genetically modified microorganism or organism thatcontains or is capable of providing a source of carbohydrates (e.g.,cellulose), for example, protists, e.g., animal protists (e.g., protozoasuch as flagellates, amoeboids, ciliates, and sporozoa) and plantprotists (e.g., algae such alveolates, chlorarachniophytes,cryptomonads, euglenids, glaucophytes, haptophytes, red algae,stramenopiles, and viridaeplantae). Other examples include seaweed,plankton (e.g., macroplankton, mesoplankton, microplankton,nanoplankton, picoplankton, and femtoplankton), phytoplankton, bacteria(e.g., gram positive bacteria, gram negative bacteria, andextremophiles), yeast and/or mixtures of these. In some instances,microbial biomass can be obtained from natural sources, e.g., the ocean,lakes, bodies of water, e.g., salt water or fresh water, or on land.Alternatively or in addition, microbial biomass can be obtained fromculture systems, e.g., large scale dry and wet culture and fermentationsystems. In other embodiments, the biomass materials, such ascellulosic, starchy and lignocellulosic feedstock materials, can beobtained from transgenic microorganisms and plants that have beenmodified with respect to a wild type variety. Such modifications may be,for example, through the iterative steps of selection and breeding toobtain desired traits in a plant. Furthermore, the plants can have hadgenetic material removed, modified, silenced and/or added with respectto the wild type variety. For example, genetically modified plants canbe produced by recombinant DNA methods, where genetic modificationsinclude introducing or modifying specific genes from parental varieties,or, for example, by using transgenic breeding wherein a specific gene orgenes are introduced to a plant from a different species of plant and/orbacteria. Another way to create genetic variation is through mutationbreeding wherein new alleles are artificially created from endogenousgenes. The artificial genes can be created by a variety of waysincluding treating the plant or seeds with, for example, chemicalmutagens (e.g., using alkylating agents, epoxides, alkaloids, peroxides,formaldehyde), irradiation (e.g., X-rays, gamma rays, neutrons, betaparticles, alpha particles, protons, deuterons, UV radiation) andtemperature shocking or other external stressing and subsequentselection techniques. Other methods of providing modified genes isthrough error prone PCR and DNA shuffling followed by insertion of thedesired modified DNA into the desired plant or seed. Methods ofintroducing the desired genetic variation in the seed or plant include,for example, the use of a bacterial carrier, biolistics, calciumphosphate precipitation, electroporation, gene splicing, gene silencing,lipofection, microinjection and viral carriers. Additional geneticallymodified materials have been described in U.S. application Ser. No13/396,369 filed Feb. 14, 2012 the full disclosure of which isincorporated herein by reference. Any of the methods described hereincan be practiced with mixtures of any biomass materials describedherein.

Biomass Material Preparation—Mechanical Treatments

The biomass can be in a dry form, for example, with less than about 35%moisture content (e.g., less than about 20%, less than about 15%, lessthan about 10% less than about 5%, less than about 4%, less than about3%, less than about 2% or even less than about 1%). The biomass can alsobe delivered in a wet state, for example, as a wet solid, a slurry or asuspension with at least about 10 wt. % solids (e.g., at least about 20wt. %, at least about 30 wt. %, at least about 40 wt. %, at least about50 wt. %, at least about 60 wt. %, at least about 70 wt. %).

The processes disclosed herein can utilize low bulk density materials,for example, cellulosic or lignocellulosic feedstocks that have beenphysically pretreated to have a bulk density of less than about 0.75g/cm³, e.g., less than about 0.7, 0.65, 0.60, 0.50, 0.35, 0.25, 0.20,0.15, 0.10, 0.05 or less, e.g., less than about 0.025 g/cm³. Bulkdensity is determined using AS™ D1895B. Briefly, the method involvesfilling a measuring cylinder of known volume with a sample and obtaininga weight of the sample. The bulk density is calculated by dividing theweight of the sample in grams by the known volume of the cylinder incubic centimeters. If desired, low bulk density materials can bedensified, for example, by methods described in U.S. Pat. No. 7,971,809to Medoff, the full disclosure of which is hereby incorporated byreference.

In some cases, the pre-treatment processing includes screening of thebiomass material. Screening can be through a mesh or perforated platewith a desired opening size, for example, less than about 6.35 mm (¼inch, 0.25 inch), (e.g., less than about 3.18 mm (⅛ inch, 0.125 inch),less than about 1.59 mm ( 1/16 inch, 0.0625 inch), is less than about0.79 mm ( 1/32 inch, 0.03125 inch), e.g., less than about 0.51 mm ( 1/50inch, 0.02000 inch), less than about 0.40 mm ( 1/64 inch, 0.015625inch), less than about 0.23 mm (0.009 inch), less than about 0.20 mm (1/128 inch, 0.0078125 inch), less than about 0.18 mm (0.007 inch), lessthan about 0.13 mm (0.005 inch), or even less than about 0.10 mm ( 1/256inch, 0.00390625 inch)). In one configuration the desired biomass fallsthrough the perforations or screen and thus biomass larger than theperforations or screen are not irradiated. These larger materials can bere-processed, for example, by comminuting, or they can simply be removedfrom processing. In another configuration material that is larger thanthe perforations is irradiated and the smaller material is removed bythe screening process or recycled. In this kind of a configuration, theconveyor itself (for example, a part of the conveyor) can be perforatedor made with a mesh. For example, in one particular embodiment thebiomass material may be wet and the perforations or mesh allow water todrain away from the biomass before irradiation.

Screening of material can also be by a manual method, for example, by anoperator or mechanoid (e.g., a robot equipped with a color, reflectivityor other sensor) that removes unwanted material. Screening can also beby magnetic screening wherein a magnet is disposed near the conveyedmaterial and the magnetic material is removed magnetically.

Optional pre-treatment processing can include heating the material. Forexample, a portion of a conveyor conveying the biomass or other materialcan be sent through a heated zone. The heated zone can be created, forexample, by IR radiation, microwaves, combustion (e.g., gas, coal, oil,biomass), resistive heating and/or inductive coils. The heat can beapplied from at least one side or more than one side, can be continuousor periodic and can be for only a portion of the material or all thematerial. For example, a portion of the conveying trough can be heatedby use of a heating jacket. Heating can be, for example, for the purposeof drying the material. In the case of drying the material, this canalso be facilitated, with or without heating, by the movement of a gas(e.g., air, oxygen, nitrogen, He, CO₂, Argon) over and/or through thebiomass as it is being conveyed.

Optionally, pre-treatment processing can include cooling the material.Cooling material is described in U.S. Pat. No. 7,900,857 to Medoff, thedisclosure of which in incorporated herein by reference. For example,cooling can be by supplying a cooling fluid, for example, water (e.g.,with glycerol), or nitrogen (e.g., liquid nitrogen) to the bottom of theconveying trough. Alternatively, a cooling gas, for example, chillednitrogen can be blown over the biomass materials or under the conveyingsystem.

Another optional pre-treatment processing method can include adding amaterial to the biomass or other feedstocks. The additional material canbe added by, for example, by showering, sprinkling and or pouring thematerial onto the biomass as it is conveyed. Materials that can be addedinclude, for example, metals, ceramics and/or ions as described in U.S.Pat. App. Pub. 2010/0105119 A1 (filed Oct. 26, 2009) and U.S. Pat. App.Pub. 2010/0159569 A1 (filed Dec. 16, 2009), the entire disclosures ofwhich are incorporated herein by reference. Optional materials that canbe added include acids and bases. Other materials that can be added areoxidants (e.g., peroxides, chlorates), polymers, polymerizable monomers(e.g., containing unsaturated bonds), water, catalysts, enzymes and/ororganisms. Materials can be added, for example, in pure form, as asolution in a solvent (e.g., water or an organic solvent) and/or as asolution. In some cases the solvent is volatile and can be made toevaporate e.g., by heating and/or blowing gas as previously described.The added material may form a uniform coating on the biomass or be ahomogeneous mixture of different components (e.g., biomass andadditional material). The added material can modulate the subsequentirradiation step by increasing the efficiency of the irradiation,damping the irradiation or changing the effect of the irradiation (e.g.,from electron beams to X-rays or heat). The method may have no impact onthe irradiation but may be useful for further downstream processing. Theadded material may help in conveying the material, for example, bylowering dust levels.

Biomass can be delivered to a conveyor (e.g., vibratory conveyors usedin the vaults herein described) by a belt conveyor, a pneumaticconveyor, a screw conveyor, a hopper, a pipe, manually or by acombination of these. The biomass can, for example, be dropped, pouredand/or placed onto the conveyor by any of these methods. In someembodiments the material is delivered to the conveyor using an enclosedmaterial distribution system to help maintain a low oxygen atmosphereand/or control dust and fines. Lofted or air suspended biomass fines anddust are undesirable because these can form an explosion hazard ordamage the window foils of an electron gun (if such a device is used fortreating the material).

The material can be leveled to form a uniform thickness between about0.0312 and 5 inches (e.g., between about 0.0625 and 2.000 inches,between about 0.125 and 1 inches, between about 0.125 and 0.5 inches,between about 0.3 and 0.9 inches, between about 0.2 and 0.5 inchesbetween about 0.25 and 1.0 inches, between about 0.25 and 0.5 inches,0.100+/−0.025 inches, 0.150+/−0.025 inches, 0.200+/−0.025 inches,0.250+/−0.025 inches, 0.300+/−0.025 inches, 0.350+/−0.025 inches,0.400+/−0.025 inches, 0.450+/−0.025 inches, 0.500+/−0.025 inches,0.550+/−0.025 inches, 0.600+/−0.025 inches, 0.700+/−0.025 inches,0.750+/−0.025 inches, 0.800+/−0.025 inches, 0.850+/−0.025 inches,0.900+/−0.025 inches, 0.900+/−0.025 inches.

Generally, it is preferred to convey the material as quickly as possiblethrough the electron beam to maximize throughput. For example, thematerial can be conveyed at rates of at least 1 ft./min, e.g., at least2 ft./min, at least 3 ft./min, at least 4 ft./min, at least 5 ft./min,at least 10 ft./min, at least 15 ft./min, 20, 25, 30, 35, 40, 45, 50ft./min. The rate of conveying is related to the beam current, forexample, for a ¼ inch thick biomass and 100 mA, the conveyor can move atabout 20 ft /min to provide a useful irradiation dosage, at 50 mA theconveyor can move at about 10 ft /min to provide approximately the sameirradiation dosage.

After the biomass material has been conveyed through the radiation zone,optional post-treatment processing can be done. The optionalpost-treatment processing can, for example, be a process described withrespect to the pre-irradiation processing. For example, the biomass canbe screened, heated, cooled, and/or combined with bio-additives.Uniquely to post-irradiation, quenching of the radicals can occur, forexample, quenching of radicals by the addition of fluids or gases (e.g.,oxygen, nitrous oxide, ammonia, liquids), using pressure, heat, and/orthe addition of radical scavengers. For example, the biomass can beconveyed out of the enclosed conveyor and exposed to a gas (e.g.,oxygen) where it is quenched, forming carboxylated groups. In oneembodiment the biomass is exposed during irradiation to the reactive gasor fluid. Quenching of biomass that has been irradiated is described inU.S. Pat. No. 8,083,906 to Medoff, the entire disclosure of which isincorporate herein by reference.

If desired, one or more mechanical treatments can be used in addition toirradiation to further reduce the recalcitrance of thecarbohydrate-containing material. These processes can be applied before,during and or after irradiation.

In some cases, the mechanical treatment may include an initialpreparation of the feedstock as received, e.g., size reduction ofmaterials, such as by comminution, e.g., cutting, grinding, shearing,pulverizing or chopping. For example, in some cases, loose feedstock(e.g., recycled paper, starchy materials, or switchgrass) is prepared byshearing or shredding. Mechanical treatment may reduce the bulk densityof the carbohydrate-containing material, increase the surface area ofthe carbohydrate-containing material and/or decrease one or moredimensions of the carbohydrate-containing material.

Alternatively, or in addition, the feedstock material can be treatedwith another treatment, for example, chemical treatments, such as withan acid (HCl, H₂SO₄, H₃PO₄), a base (e.g., KOH and NaOH), a chemicaloxidant (e.g., peroxides, chlorates, ozone), irradiation, steamexplosion, pyrolysis, heat treatment, sonication, oxidation, chemicaltreatment. The treatments can be in any order and in any sequence andcombinations. For example, the feedstock material can first bephysically treated by one or more treatment methods, e.g., chemicaltreatment including and in combination with acid hydrolysis (e.g.,utilizing HCl, H₂SO₄, H₃PO₄), radiation, heat treatment, sonication,oxidation, pyrolysis or steam explosion, and then mechanically treated.This sequence can be advantageous since materials treated by one or moreof the other treatments, e.g., irradiation or pyrolysis, tend to be morebrittle and, therefore, it may be easier to further change the structureof the material by mechanical treatment. As another example, a feedstockmaterial can be conveyed through ionizing radiation using a conveyor asdescribed herein and then mechanically treated. Chemical treatment canremove some or all of the lignin (for example, chemical pulping) and canpartially or completely hydrolyze the material. The methods also can beused with pre-hydrolyzed material. The methods also can be used withmaterial that has not been pre hydrolyzed The methods can be used withmixtures of hydrolyzed and non-hydrolyzed materials, for example, withabout 50% or more non-hydrolyzed material, with about 60% or morenon-hydrolyzed material, with about 70% or more non-hydrolyzed material,with about 80% or more non-hydrolyzed material or even with 90% or morenon-hydrolyzed material

In addition to size reduction, which can be performed initially and/orlater in processing, mechanical treatment can also be advantageous for“opening up,” “stressing,” breaking or shattering thecarbohydrate-containing materials, making the cellulose of the materialsmore susceptible to chain scission and/or disruption of crystallinestructure during the physical treatment.

Methods of mechanically treating the carbohydrate-containing materialinclude, for example, milling or grinding. Milling may be performedusing, for example, a hammer mill, ball mill, colloid mill, conical orcone mill, disk mill, edge mill, Wiley mill, grist mill or other mill.Grinding may be performed using, for example, a cutting/impact typegrinder. Some exemplary grinders include stone grinders, pin grinders,coffee grinders, and burr grinders. Grinding or milling may be provided,for example, by a reciprocating pin or other element, as is the case ina pin mill Other mechanical treatment methods include mechanical rippingor tearing, other methods that apply pressure to the fibers, and airattrition milling. Suitable mechanical treatments further include anyother technique that continues the disruption of the internal structureof the material that was initiated by the previous processing steps.

Mechanical feed preparation systems can be configured to produce streamswith specific characteristics such as, for example, specific maximumsizes, specific length-to-width, or specific surface areas ratios.Physical preparation can increase the rate of reactions, improve themovement of material on a conveyor, improve the irradiation profile ofthe material, improve the radiation uniformity of the material, orreduce the processing time required by opening up the materials andmaking them more accessible to processes and/or reagents, such asreagents in a solution.

The bulk density of feedstocks can be controlled (e.g., increased). Insome situations, it can be desirable to prepare a low bulk densitymaterial, e.g., by densifying the material (e.g., densification can makeit easier and less costly to transport to another site) and thenreverting the material to a lower bulk density state (e.g., aftertransport). The material can be densified, for example, from less thanabout 0.2 g/cc to more than about 0.9 g/cc (e.g., less than about 0.3 tomore than about 0.5 g/cc, less than about 0.3 to more than about 0.9g/cc, less than about 0.5 to more than about 0.9 g/cc, less than about0.3 to more than about 0.8 g/cc, less than about 0.2 to more than about0.5 g/cc). For example, the material can be densified by the methods andequipment disclosed in U.S. Pat. No. 7,932,065 to Medoff andInternational Publication No. WO 2008/073186 (which was filed Oct. 26,2007, was published in English, and which designated the United States),the full disclosures of which are incorporated herein by reference.Densified materials can be processed by any of the methods describedherein, or any material processed by any of the methods described hereincan be subsequently densified.

In some embodiments, the material to be processed is in the form of afibrous material that includes fibers provided by shearing a fibersource. For example, the shearing can be performed with a rotary knifecutter.

For example, a fiber source, e.g., that is recalcitrant or that has hadits recalcitrance level reduced, can be sheared, e.g., in a rotary knifecutter, to provide a first fibrous material. The first fibrous materialis passed through a first screen, e.g., having an average opening sizeof 1.59 mm or less ( 1/16 inch, 0.0625 inch), provide a second fibrousmaterial. If desired, the fiber source can be cut prior to the shearing,e.g., with a shredder. For example, when a paper is used as the fibersource, the paper can be first cut into strips that are, e.g., ¼- to½-inch wide, using a shredder, e.g., a counter-rotating screw shredder,such as those manufactured by Munson (Utica, N.Y.). As an alternative toshredding, the paper can be reduced in size by cutting to a desired sizeusing a guillotine cutter. For example, the guillotine cutter can beused to cut the paper into sheets that are, e.g., 10 inches wide by 12inches long.

In some embodiments, the shearing of the fiber source and the passing ofthe resulting first fibrous material through a first screen areperformed concurrently. The shearing and the passing can also beperformed in a batch-type process.

For example, a rotary knife cutter can be used to concurrently shear thefiber source and screen the first fibrous material. A rotary knifecutter includes a hopper that can be loaded with a shredded fiber sourceprepared by shredding a fiber source.

In some implementations, the feedstock is physically treated prior tosaccharification and/or fermentation. Physical treatment processes caninclude one or more of any of those described herein, such as mechanicaltreatment, chemical treatment, irradiation, heat treatment, sonication,oxidation, pyrolysis or steam explosion. Treatment methods can be usedin combinations of two, three, four, or even all of these technologies(in any order). When more than one treatment method is used, the methodscan be applied at the same time or at different times. Other processesthat change a molecular structure of a biomass feedstock may also beused, alone or in combination with the processes disclosed herein.

Mechanical treatments that may be used, and the characteristics of themechanically treated carbohydrate-containing materials, are described infurther detail in U.S. Pat. App. Pub. 2012/0100577 A1, filed Oct. 18,2011, the full disclosure of which is hereby incorporated herein byreference.

The mechanical treatments described herein can also be applied toprocessing of hydroxyl-carboxylic polymers and hydroxyl-carboxylicpolymers based materials.

Sonication, Pyrolysis, Oxidation, Steam Explosion

If desired, one or more sonication, pyrolysis, oxidative, or steamexplosion processes can be used instead of or in addition to irradiationto reduce or further reduce the recalcitrance of thecarbohydrate-containing material. For example, these processes can beapplied before, during and or after irradiation. These processes aredescribed in detail in U.S. Pat. No. 7,932,065 to Medoff, the fulldisclosure of which is incorporated herein by reference.

Heat Treatment of Biomass

Alternately, or in addition to the biomass may be heat treated for up totwelve hours at temperatures ranging from about 90° C. to about 160° C.Optionally, this heat treatment step is performed after biomass has beenirradiated with an electron beam. The amount of time for the heattreatment is up to 9 hours, alternately up to 6 hours, optionally up to4 hours and further up to about 2 hours. The treatment time can be up toas little as 30 minutes when the mass may be effectively heated.

The heat treatment can be performed 90° C. to about 160° C. or,optionally, at 100 to 150 or, alternatively, at 120 to 140° C. Thebiomass is suspended in water such that the biomass content is 10 to 75wt. % in water. In the case of the biomass being the irradiated biomasswater is added and the heat treatment performed.

The heat treatment is performed in an aqueous suspension or mixture ofthe biomass. The amount of biomass is 10 to 90 wt. % of the totalmixture, alternatively 20 to 70 wt. % or optionally 25 to 50 wt. %. Theirradiated biomass may have minimal water content so water must be addedprior to the heat treatment.

Since at temperatures above 100° C. there will be pressure vesselrequired to accommodate the pressure due to the vaporized of water. Theprocess for the heat treatment may be batch, continuous, semi-continuousor other reactor configurations. The continuous reactor configurationmay be a tubular reactor and may include device(s) within the tube whichwill facilitate heat transfer and mixing/suspension of the biomass.These tubular devices may include a one or more static mixers. The heatmay also be put into the system by direct injection of steam.

Use of Treated Biomass Material

Using the methods described herein, a starting biomass material (e.g.,plant biomass, animal biomass, paper, and municipal waste biomass) canbe used as feedstock to produce useful intermediates and products suchas organic acids, salts of organic acids, hydroxyl-carboxylic acids,(for instance, lactic acid), acid anhydrides, esters of organic acidsand fuels, e.g., fuels for internal combustion engines or feedstocks forfuel cells. Systems and processes are described herein that can use asfeedstock cellulosic and/or lignocellulosic materials that are readilyavailable, but often can be difficult to process, e.g., municipal wastestreams and waste paper streams, such as streams that include newspaper,kraft paper, corrugated paper or mixtures of these.

In order to convert the feedstock to a form that can be readilyprocessed, the glucan- or xylan-containing cellulose in the feedstockcan be hydrolyzed to low molecular weight carbohydrates, such as sugars,by a saccharifying agent, e.g., an enzyme or acid, a process referred toas saccharification. The low molecular weight carbohydrates can then beused, for example, in an existing manufacturing plant, such as a singlecell protein plant, an enzyme manufacturing plant, or a fuel plant,e.g., an ethanol manufacturing facility.

The feedstock can be hydrolyzed using an enzyme, e.g., by combining thematerials and the enzyme in a solvent, e.g., in an aqueous solution.

Alternatively, the enzymes can be supplied by organisms that break downbiomass, such as the cellulose and/or the lignin portions of thebiomass, contain or manufacture various cellulolytic enzymes(cellulases), ligninases or various small molecule biomass-degradingmetabolites. These enzymes may be a complex of enzymes that actsynergistically to degrade crystalline cellulose or the lignin portionsof biomass. Examples of cellulolytic enzymes include: endoglucanases,cellobiohydrolases, and cellobiases (beta-glucosidases).

During saccharification a cellulosic substrate can be initiallyhydrolyzed by endoglucanases at random locations producing oligomericintermediates. These intermediates are then substrates for exo-splittingglucanases such as cellobiohydrolase to produce cellobiose from the endsof the cellulose polymer. Cellobiose is a water-soluble 1,4-linked dimerof glucose. Finally, cellobiase cleaves cellobiose to yield glucose. Theefficiency (e.g., time to hydrolyze and/or completeness of hydrolysis)of this process depends on the recalcitrance of the cellulosic material.

Lignin Derived Products

The spent biomass (e.g., spent lignocellulosic material) fromlignocellulosic processing by the methods described are expected to havea high lignin content and in addition to being useful for producingenergy through combustion in a Co-Generation plant, may have uses asother valuable products. The spent biomass can be a by-product from theprocess of producing the hydroxyl-carboxylic acid monomer. For example,the lignin can be used as captured as a plastic, or it can besynthetically upgraded to other plastics. In some instances, it can alsobe converted to lignosulfonates, which can be utilized as binders,dispersants, emulsifiers or as sequestrants.

When used as a binder, the lignin or a lignosulfonate can, e.g., beutilized in coal briquettes, in ceramics, for binding carbon black, forbinding fertilizers and herbicides, as a dust suppressant, in the makingof plywood and particle board, for binding animal feeds, as a binder forfiberglass, as a binder in linoleum paste and as a soil stabilizer.

As a dispersant, the lignin or lignosulfonates can be used, e.g.,concrete mixes, clay and ceramics, dyes and pigments, leather tanningand in gypsum board.

As an emulsifier, the lignin or lignosulfonates can be used, e.g., inasphalt, pigments and dyes, pesticides and wax emulsions.

As a sequestrant, the lignin or lignosulfonates can be used, e.g., inmicro-nutrient systems, cleaning compounds and water treatment systems,e.g., for boiler and cooling systems.

For energy production lignin generally has a higher energy content thanholocellulose (cellulose and hemicellulose) since it contains morecarbon than homocellulose. For example, dry lignin can have an energycontent of between about 11,000 and 12,500 BTU per pound, compared to7,000 an 8,000 BTU per pound of holocellulose. As such, lignin can bedensified and converted into briquettes and pellets for burning. Forexample, the lignin can be converted into pellets by any methoddescribed herein. For a slower burning pellet or briquette, the lignincan be crosslinked, such as applying a radiation dose of between about0.5 Mrad and 5 Mrad. Crosslinking can make a slower burning form factor.The form factor, such as a pellet or briquette, can be converted to a“synthetic coal” or charcoal by pyrolyzing in the absence of air, e.g.,at between 400 and 950° C. Prior to pyrolyzing, it can be desirable tocrosslink the lignin to maintain structural integrity.

Co-generation using spent biomass is described in International App. No.PCT/US2014/021634 filed Mar. 7, 2014, the entire disclosure therein isherein incorporated by reference.

Lignin derived products can also be combined with poly hydroxycarboxylicacid and poly hydroxycarboxylic acid derived products. (e.g., polyhydroxycarboxylic acid that has been produced as described herein). Forexample, lignin and lignin derived products can be blended, grafted toor otherwise combined and/or mixed with poly hydroxycarboxylic acid. Thelignin can, for example, be useful for strengthening, plasticizing orotherwise modifying the poly hydroxycarboxylic acid.

Saccharification

In order to convert the feedstock to a form that can be readilyprocessed, the glucan- or xylan-containing cellulose in the feedstockcan be hydrolyzed to low molecular weight carbohydrates, such as sugars,by a saccharifying agent, e.g., an enzyme or acid, a process referred toas saccharification. The low molecular weight carbohydrates can then beused, for example, in an existing manufacturing plant, such as a singlecell protein plant, an enzyme manufacturing plant, or a fuel plant,e.g., an ethanol manufacturing facility.

The feedstock can be hydrolyzed using an enzyme, e.g., by combining thematerials and the enzyme in a solvent, e.g., in an aqueous solution.

Alternatively, the enzymes can be supplied by organisms that break downbiomass, such as the cellulose and/or the lignin portions of thebiomass, contain or manufacture various cellulolytic enzymes(cellulases), ligninases or various small molecule biomass-degradingmetabolites. These enzymes may be a complex of enzymes that actsynergistically to degrade crystalline cellulose or the lignin portionsof biomass. Examples of cellulolytic enzymes include: endoglucanases,cellobiohydrolases, and cellobiases (beta-glucosidases).

During saccharification a cellulosic substrate can be initiallyhydrolyzed by endoglucanases at random locations producing oligomericintermediates. These intermediates are then substrates for exo-splittingglucanases such as cellobiohydrolase to produce cellobiose from the endsof the cellulose polymer. Cellobiose is a water-soluble 1,4-linked dimerof glucose. Finally, cellobiase cleaves cellobiose to yield glucose. Theefficiency (e.g., time to hydrolyze and/or completeness of hydrolysis)of this process depends on the recalcitrance of the cellulosic material.

Therefore, the treated biomass materials can be saccharified, generallyby combining the material and a cellulase enzyme in a fluid medium,e.g., an aqueous solution. In some cases, the material is boiled,steeped, or cooked in hot water prior to saccharification, as describedin U.S. Pat. App. Pub. 2012/0100577 A1 by Medoff and Masterman,published on Apr. 26, 2012, the entire contents of which areincorporated herein.

The saccharification may be done by inoculating a raw sugar mixtureproduced by saccharifying a reduced recalcitrance lignocellulosicmaterial to produce a hydroxy-carboxylic acid. The hydroxy-carboxylicacid can be selected from the group glycolic acid, D-lactic acid,L-lactic acid, D-malic acid, L-malic, citric acid and D-tartaric acid,L-tartaric acid, and meso-tartaric acid. The raw sugar mixture can bethe reduced recalcitrance lignocellulosic material which was processedby irradiating the lignocellulosic material with an electron beam.

The saccharification process can be partially or completely performed ina tank (e.g., a tank having a volume of at least 4000, 40,000, or500,000 L) in a manufacturing plant, and/or can be partially orcompletely performed in transit, e.g., in a rail car, tanker truck, orin a supertanker or the hold of a ship. The time required for completesaccharification will depend on the process conditions and thecarbohydrate-containing material and enzyme used. If saccharification isperformed in a manufacturing plant under controlled conditions, thecellulose may be substantially entirely converted to sugar, e.g.,glucose in about 12-96 hours. If saccharification is performed partiallyor completely in transit, saccharification may take longer.

It is generally preferred that the tank contents be mixed duringsaccharification, e.g., using jet mixing as described in InternationalApp. No. PCT/US2010/035331, filed May 18, 2010, which was published inEnglish as WO 2010/135380 and designated the United States, the fulldisclosure of which is incorporated by reference herein.

The addition of surfactants can enhance the rate of saccharification.Examples of surfactants include non-ionic surfactants, such as a Tween®20 or Tween® 80 polyethylene glycol surfactants, ionic surfactants, oramphoteric surfactants.

It is generally preferred that the concentration of the sugar solutionresulting from saccharification be relatively high, e.g., greater than40%, or greater than 50, 60, 70, 80, 90 or even greater than 95% byweight. Water may be removed, e.g., by evaporation, to increase theconcentration of the sugar solution. This reduces the volume to beshipped, and also inhibits microbial growth in the solution.

Alternatively, sugar solutions of lower concentrations may be used, inwhich case it may be desirable to add an antimicrobial additive, e.g., abroad spectrum antibiotic, in a low concentration, e.g., 50 to 150 ppm.Other suitable antibiotics include amphotericin B, ampicillin,chloramphenicol, ciprofloxacin, gentamicin, hygromycin B, kanamycin,neomycin, penicillin, puromycin, streptomycin. Antibiotics will inhibitgrowth of microorganisms during transport and storage, and can be usedat appropriate concentrations, e.g., between 15 and 1000 ppm by weight,e.g., between 25 and 500 ppm, or between 50 and 150 ppm. If desired, anantibiotic can be included even if the sugar concentration is relativelyhigh. Alternatively, other bio-additives with anti-microbial ofpreservative properties may be used. Preferably the antimicrobialadditive(s) are food-grade.

A relatively high concentration solution can be obtained by limiting theamount of water added to the carbohydrate-containing material with theenzyme. The concentration can be controlled, e.g., by controlling howmuch saccharification takes place. For example, concentration can beincreased by adding more carbohydrate-containing material to thesolution. In order to keep the sugar that is being produced in solution,a surfactant can be added, e.g., one of those discussed above.Solubility can also be increased by increasing the temperature of thesolution. For example, the solution can be maintained at a temperatureof 40-50° C., 60-80° C., or even higher.

Saccharifying Agents

Suitable cellulolytic enzymes include cellulases from species in thegenera Bacillus, Coprinus, Myceliophthora, Cephalosporium, Scytalidium,Penicillium, Aspergillus, Pseudomonas, Humicola, Fusarium, Thielavia,Acremonium, Chrysosporium and Trichoderma, especially those produced bya strain selected from the species Aspergillus (see, e.g., EP Pub. No. 0458 162), Humicola insolens (reclassified as Scytalidium thermophilum,see, e.g., U.S. Pat. No. 4,435,307), Coprinus cinereus, Fusariumoxysporum, Myceliophthora thermophila, Meripilus giganteus, Thielaviaterrestris, Acremonium sp. (including, but not limited to, A.persicinum, A. acremonium, A. brachypenium, A. dichromosporum, A.obclavatum, A. pinkertoniae, A. roseogriseum, A. incoloratum, and A.furatum). Preferred strains include Humicola insolens DSM 1800, Fusariumoxysporum DSM 2672, Myceliophthora thermophila CBS 117.65,Cephalosporium sp. RYM-202, Acremonium sp. CBS 478.94, Acremonium sp.CBS 265.95, Acremonium persicinum CBS 169.65, Acremonium acremonium AHU9519, Cephalosporium sp. CBS 535.71, Acremonium brachypenium CBS 866.73,Acremonium dichromosporum CBS 683.73, Acremonium obclavatum CBS 311.74,Acremonium pinkertoniae CBS 157.70, Acremonium roseogriseum CBS 134.56,Acremonium incoloratum CBS 146.62, and Acremonium furatum CBS 299.70H.Cellulolytic enzymes may also be obtained from Chrysosporium, preferablya strain of Chrysosporium lucknowense. Additional strains that can beused include, but are not limited to, Trichoderma (particularly T.viride, T. reesei, and T. koningii), alkalophilic Bacillus (see, forexample, U.S. Pat. No. 3,844,890 and EP Pub. No. 0 458 162), andStreptomyces (see, e.g., EP Pub. No. 0 458 162).

In addition to or in combination to enzymes, acids, bases and otherchemicals (e.g., oxidants) can be utilized to saccharify lignocellulosicand cellulosic materials. These can be used in any combination orsequence (e.g., before, after and/or during addition of an enzyme). Forexample, strong mineral acids can be utilized (e.g. HCl, H₂SO₄, H₃PO₄)and strong bases (e.g., NaOH, KOH).

In the processes described herein, for example, after saccharification,sugars (e.g., glucose and xylose) can be isolated. For example, sugarscan be isolated by precipitation, crystallization, chromatography (e.g.,simulated moving bed chromatography, high pressure chromatography),centrifugation, extraction, any other isolation method known in the art,and combinations thereof.

Fermentation

Yeast and Zymomonas bacteria, for example, can be used for fermentationor conversion of sugar(s) to alcohol(s). Other microorganisms arediscussed below. The optimum pH for fermentations is about pH 4 to 7.For example, the optimum pH for yeast is from about pH 4 to 5, while theoptimum pH for Zymomonas is from about pH 5 to 6. Typical fermentationtimes are about 24 to 168 hours (e.g., 24 to 96 hrs.) with temperaturesin the range of 20° C. to 40° C. (e.g., 26° C. to 40° C.), howeverthermophilic microorganisms prefer higher temperatures.

In some embodiments, e.g., when anaerobic organisms are used, at least aportion of the fermentation is conducted in the absence of oxygen, e.g.,under a blanket of an inert gas such as N₂, Ar, He, CO₂ or mixturesthereof. Additionally, the mixture may have a constant purge of an inertgas flowing through the tank during part of or all of the fermentation.In some cases, anaerobic condition, can be achieved or maintained bycarbon dioxide production during the fermentation and no additionalinert gas is needed.

In some embodiments, all or a portion of the fermentation process can beinterrupted before the low molecular weight sugar is completelyconverted to a product (e.g., ethanol). The intermediate fermentationproducts include sugar and carbohydrates in high concentrations. Thesugars and carbohydrates can be isolated via any means known in the art.These intermediate fermentation products can be used in preparation offood for human or animal consumption. Additionally or alternatively, theintermediate fermentation products can be ground to a fine particle sizein a stainless-steel laboratory mill to produce a flour-like substance.Jet mixing may be used during fermentation, and in some casessaccharification and fermentation are performed in the same tank.

Nutrients for the microorganisms may be added during saccharificationand/or fermentation, for example, the food-based nutrient packagesdescribed in U.S. Pat. App. Pub. 2012/0052536, filed Jul. 15, 2011, thecomplete disclosure of which is incorporated herein by reference.

“Fermentation” includes the methods and products that are disclosed inInternational App. No. PCT/US2012/071093 filed Dec. 20, 2012 andInternational App. No. PCT/US2012/071097 filed Dec. 12, 2012, thecontents of both of which are incorporated by reference herein in theirentirety.

Mobile fermenters can be utilized, as described in International App.No. PCT/US2007/074028 (which was filed Jul. 20, 2007, was published inEnglish as WO 2008/011598 and designated the United States) and has aU.S. Pat. No. 8,318,453, the contents of which are incorporated hereinin its entirety. Similarly, the saccharification equipment can bemobile. Further, saccharification and/or fermentation may be performedin part or entirely during transit.

Fermentation Agents

The microorganism(s) used in fermentation can be naturally-occurringmicroorganisms and/or engineered microorganisms. For example, themicroorganism can be a bacterium (including, but not limited to, e.g., acellulolytic bacterium), a fungus, (including, but not limited to, e.g.,a yeast), a plant, a protist, e.g., a protozoa or a fungus-like protest(including, but not limited to, e.g., a slime mold), or an alga. Whenthe organisms are compatible, mixtures of organisms can be utilized.

Suitable fermenting microorganisms have the ability to convertcarbohydrates, such as glucose, fructose, xylose, arabinose, mannose,galactose, oligosaccharides or polysaccharides into fermentationproducts. Fermenting microorganisms include strains of the genusSaccharomyces spp. (including, but not limited to, S. cerevisiae(baker's yeast), S. distaticus, S. uvarum), the genus Kluyveromyces,(including, but not limited to, K. marxianus, K. fragilis), the genusCandida (including, but not limited to, C. pseudotropicalis, and C.brassicae), Pichia stipitis (a relative of Candida shehatae), the genusClavispora (including, but not limited to, C. lusitaniae and C.opuntiae), the genus Pachysolen (including, but not limited to, P.tannophilus), the genus Bretannomyces (including, but not limited to,e.g., B. clausenii (Philippidis, G. P., 1996, Cellulose bioconversiontechnology, in Handbook on Bioethanol: Production and Utilization,Wyman, C. E., ed., Taylor & Francis, Washington, D.C., 179-212)). Othersuitable microorganisms include, for example, Zymomonas mobilis,Clostridium spp. (including, but not limited to, C. thermocellum(Philippidis, 1996, supra), C. saccharobutylacetonicum, C. tyrobutyricumC. saccharobutylicum, C. Puniceum, C. beijernckii, and C.acetobutylicum), Moniliella spp. (including but not limited to M.pollinis, M. tomentosa, M. madida, M. nigrescens, M. oedocephali, M.megachiliensis), Yarrowia lipolytica, Aureobasidium sp.,Trichosporonoides sp., Trigonopsis variabilis, Trichosporon sp.,Moniliellaacetoabutans sp., Typhula variabilis, Candida magnoliae,Ustilaginomycetes sp., Pseudozyma tsukubaensis, yeast species of generaZygosaccharomyces, Debaryomyces, Hansenula and Pichia, and fungi of thedematioid genus Torula (e.g., T. corallina).

Many such microbial strains are publicly available, either commerciallyor through depositories such as the ATCC (American Type CultureCollection, Manassas, Va., USA), the NRRL (Agricultural Research ServiceCulture Collection, Peoria, Ill., USA), or the DSMZ (Deutsche Sammlungvon Mikroorganismen and Zellkulturen GmbH, Braunschweig, Germany), toname a few.

Commercially available yeasts include, for example, Red Star®/LesaffreEthanol Red (available from Red Star/Lesaffre, USA), FALI® (availablefrom Fleischmann's Yeast, a division of Burns Philip Food Inc., USA),SUPERSTART® (available from Alltech, now Lalemand), GERT STRAND®(available from Gert Strand AB, Sweden) and FERMOL® (available from DSMSpecialties).

Distillation

After fermentation, the resulting fluids can be distilled using, forexample, a “beer column” to separate ethanol and other alcohols from themajority of water and residual solids. The vapor exiting the beer columncan be, e.g., 35% by weight ethanol and can be fed to a rectificationcolumn A mixture of nearly azeotropic (92.5%) ethanol and water from therectification column can be purified to pure (99.5%) ethanol usingvapor-phase molecular sieves. The beer column bottoms can be sent to thefirst effect of a three-effect evaporator. The rectification columnreflux condenser can provide heat for this first effect. After the firsteffect, solids can be separated using a centrifuge and dried in a rotarydryer. A portion (25%) of the centrifuge effluent can be recycled tofermentation and the rest sent to the second and third evaporatoreffects. Most of the evaporator condensate can be returned to theprocess as fairly clean condensate with a small portion split off towaste water treatment to prevent build-up of low-boiling compounds.

Conveying Systems

Various conveying systems can be used to convey the feedstock materials,for example, to a vault and under an electron beam in a vault. Exemplaryconveyors are belt conveyors, pneumatic conveyors, screw conveyors,carts, trains, trains or carts on rails, elevators, front loaders,backhoes, cranes, various scrapers and shovels, trucks, and throwingdevices can be used. For example, vibratory conveyors can be used invarious processes described herein, for example, as disclosed inInternational App. No. PCT/US2013/064332 filed Oct. 10, 2013, the entiredisclosure of which is herein incorporated by reference.

Other Embodiments

Any material, processes or processed materials described herein can beused to make products and/or intermediates such as composites, fillers,binders, plastic additives, adsorbents and controlled release agents.The methods can include densification, for example, by applying pressureand heat to the materials. for example, composites can be made bycombining fibrous materials with a resin or polymer (e.g., PLA). Forexample, radiation cross-linkable resin (e.g., a thermoplastic resin,PLA, and/or PLA derivatives) can be combined with a fibrous material toprovide a fibrous material/cross-linkable resin combination. Suchmaterials can be, for example, useful as building materials, protectivesheets, containers and other structural materials (e.g., molded and/orextruded products). Absorbents can be, for example, in the form ofpellets, chips, fibers and/or sheets. Adsorbents can be used, forexample, as pet bedding, packaging material or in pollution controlsystems. Controlled release matrices can also be the form of, forexample, pellets, chips, fibers and or sheets. The controlled releasematrices can, for example, be used to release drugs, biocides,fragrances. For example, composites, absorbents and control releaseagents and their uses are described in International Application No.PCT/US2006/010648, filed Mar. 23, 2006, and U.S. Pat. No. 8,074,910filed Nov. 22, 2011, the entire disclosures of which are hereinincorporated by reference.

In some instances the biomass material is treated at a first level toreduce recalcitrance, e.g., utilizing accelerated electrons, toselectively release one or more sugars (e.g., xylose). The biomass canthen be treated to a second level to release one or more other sugars(e.g., glucose). Optionally the biomass can be dried between treatments.The treatments can include applying chemical and biochemical treatmentsto release the sugars. For example, a biomass material can be treated toa level of less than about 20 Mrad (e.g., less than about 15 Mrad, lessthan about 10 Mrad, less than about 5 Mrad, less than about 2 Mrad) andthen treated with a solution of sulfuric acid, containing less than 10%sulfuric acid (e.g., less than about 9%, less than about 8%, less thanabout 7%, less than about 6%, less than about 5%, less than about 4%,less than about 3%, less than about 2%, less than about 1%, less thanabout 0.75%, less than about 0.50%, less than about 0.25%) to releasexylose. Xylose, for example, that is released into solution, can beseparated from solids and optionally the solids washed with asolvent/solution (e.g., with water and/or acidified water).

Optionally, the Solids can be dried, for example, in air and/or undervacuum optionally with heating (e.g., below about 150° C., below about120° C.) to a water content below about 25 wt. % (below about 20 wt. %,below about 15 wt. %, below about 10 wt. %, below about 5 wt. %). Thesolids can then be treated with a level of less than about 30 Mrad(e.g., less than about 25 Mrad, less than about 20 Mrad, less than about15 Mrad, less than about 10 Mrad, less than about 5 Mrad, less thanabout 1 Mrad or even not at all) and then treated with an enzyme (e.g.,a cellulase) to release glucose. The glucose (e.g., glucose in solution)can be separated from the remaining solids. The solids can then befurther processed, for example, utilized to make energy or otherproducts (e.g., lignin derived products).

EXAMPLES

L-Lactic Acid Production from Saccharified Corncob in LactobacillusSpecies.

Material and Methods Lactic Acid Producing Strains Tested:

The Lactic acid producing stains that were tested are listed in Table 2

TABLE 2 Lactic acid producing strains tested NRRL B-441 Lactobacilluscasei NRRL B-445 Lactobacillus rhamnosus NRRL B-763 Lactobacillusdelbrueckii subspecies delbrueckii ATCC 8014 Lactobacillus plantarumATCC 9649 Lactobacillus delbrueckii subspecies delbrueckii B-4525Lactobacillus delbrueckii subspecies lactis B-4390 Lactobacilluscorniformis subspecies torquens B-227 Lactobacillus pentosus B-4527Lactobacillus brevis ATCC 25745 Pediococcus pentosaceus NRRL 395Rhizopus oryzae CBS 112.07 Rhizopus oryzae CBS 127.08 Rhizopus oryzaeCBS 396.95 Rhizopus oryzae

Seed Culture

Cells from a frozen (−80° C.) cell bank were cultivated in propagationmedium (BD Difco™ Lactobacilli MRS Broth) at 37° C., with 150 rpmstiffing for 20 hours. This seed culture was transferred to a 1.2 L (oroptionally a 20 L) bioreactors charged with media as describe below.

Main Culture Media

All media included saccharified corncob that had been hammer milled andirradiated with about 35 Mrad of electron beam irradiation. For example,saccharified corn cob can be prepared as described in in InternationalApp. No. PCT/US2014/021796 filed Mar. 7, 2014, the entire disclosure ofwhich is herein incorporated by reference.

Experiments with various additional media components were also conductedusing lactobacillus casei NRRL B-44 as the lactic acid producingorganism. A 1.2 L bioreactor with 0.7 L of culture volume was used. A 1%of 20-hour-cultured seed of lactobacillus casei NRRL B-441 wasinoculated. No aeration was utilized. The temperature was maintained atabout 37° C. Antifoam 204 was also added (0.1%, 1 ml/L) at the beginningof the fermentation.

The experiments are summarized in Table 3. The media components; initialglucose concentration, nitrogen sources, yeast extract concentration,calcium carbonate, metals and inoculum size, were tested for lactic acidyield or lactic acid production rate. In addition to media components,the physical conditions; temperature, agitation, autoclave time andheating (no-autoclave) were tested for lactic acid yield. For thesemedia components and physical reaction conditions the ranges tested, thepreferred ranges for producing some lactic acid and the most preferredranges are indicated in Table 3.

TABLE 3 L-Lactic acid production in bioreactor with B-441 Media TestComponent Parameter Range-Tested Range- Range Optiona Initial glucoseLactic acid 33-85 g/L 33-75 g/L 33-52 g/L concentration concentrationNitrogen Sources Lactic acid Yeast extract, Yeast extract, Yeast extractTested concentration Malt extract, Corn Tryptone, steep, Tryptone,Peptone Peptone Yeast Extract ^(c) Lactic acid 0-10 g/L 2.5-10 g/L 2.5g/L concentration Calcium Lactic acid 0-7 wt. %/vol. % 3-7% wt. %/vol. %5 wt. %/vol. % carbonate concentration Metal Solutions Lactic acid Withor With or Without metals concentration without metals without metalsMinor Lactic acid With or With or Without minor components:concentration without minor without minor components sodium acetatecomponents components polysorbate 80, dipotassium hydrogen phosphate,triammonium citrate Inoculum Size Lactic acid 0.1-5 vol. % 1-5 vol. % 1vol. % production rate Physical Test Range- Range- Condition ParameterRange-Tested optiona alternative Temperature Lactic acid 27-47° C.27-42° C. 33-37° C. concentration Agitation (in Lactic acid 50-400 rpm50-400 rpm 100-300 rpm 1.2 L reactor) concentration Autoclave TimeLactic acid 25 min-145 min 25 min-145 min 25 min concentration Heating(no Lactic acid 50-70° C. 50-70° C. 50-70° C. autoclave) concentration^(p)Ranges produced a yield of at least 80% based on added sugars.^(b)Optional ranges produced close to 100% lactic acid (e.g., betweenabout 90 and 100%, between about 95 and 100%). ^(c) Fluka brand yeastextract was used.

The optional ranges were utilized for subsequent tests and the media isreferred to as the optional media and the physical conditions arereferred to optional physical conditions herein.

Results with Saccharified Corn Cob

A 1.2 L bioreactor charged with 0.7 L of media (Saccharified corncob,2.5 g/L yeast extract). The media and bioreactor vessel were autoclavedfor 25 min and no additional heating was used for sterilization. Inaddition a 20 L bioreactor was charged with 10 L of media. Forsterilization the media was stirred at 200 rpm while heating at 80° C.for 10 min. When the media was cool (about 37° C.) the bioreactors wereinoculated with 1 vol. % of 20-hour-culture. The fermentations wereconducted under the physical conditions (37° C., 200 rpm stirring). Noaeration was utilized. The pH remained between 5 and 6 using 5% (wt.%/vol throughout the fermentation. The temperature was maintained atabout 37° C. Antifoam 204 was also added (0.1 vol. %) at the beginningof the fermentation. Several Lactobacillus casei strains were tested(NRRL B-441, NRRL B-445, NRRL B-763 and ATCC 8014).

A plot of the sugar consumption and lactic acid production for the NRRLB-441 strain is shown in the 1.2 L bioreactor is shown in FIG. 7. Aftertwo days all of the glucose was consumed, while xylose was not consumed.Fructose and cellobiose were also consumed. Lactic acid was produced ata concentration of about 42 g/L. The consumed glucose, fructose andcellobiose (total 42 g/L) were about to same as produced lactic acid.

Similar data from results of the fermentation using the NRRL B-441strain in the 20 L bioreactor are shown in FIG. 8. Glucose wascompletely consumed while xylose was not significantly consumed. Lacticacid was produced at a final concentration of about 47-48 g/L.

Enantiomer analysis is summarized for all strains tested in Table 4.Lactobacillus casei (NRRL-B-441) and L. rhamnosus (B-445) produced morethan 96% L-lactic acid. L. delbrueckii sub. Delbrueckii (B-763) showedover 99% of the D-Lactic acid. The L. plantarum (ATCC 8014) showed anapproximate equal mixture of each enantiomer.

TABLE 4 Ratio of L and D-Lactic Acid for Various Fermenting OrganismsStrain L-Lactic Acid D-Lactic Acid L. casei (B-441) 96.1 3.9 L.rhamnosus (B-445) 98.3 1.7 L. delbrueckii sub. Delbrueckii 0.6 99.4(B-763) L. plantarum (ATCC 8014) 52.8 47.2

Comparison Example Polymerization of Lactic Acid

A 250 ml three-necked flask was equipped with a mechanical stirrer and acondenser that was connected with a vacuum system through a cold trap.100 grams of 90 wt. % aqueous L-lactic acid was dehydrated at 150° C.,first at atmospheric pressure for 2 hours, then at a reduced pressure of90 mmHg for 2 hours, and finally under a pressure of 20 mmHg for another4 hours. A clear viscous liquid of oligo (L-lactic acid) was formedquantitatively.

400 mg (0.4 wt. %) of both tin(II) chloride dihydrate and para-toluenesulfonic acid was acid was added to the mixture and further heatedto180° C. for 5 hours at 8 mmHg. With the reaction proceeding, thesystem became more viscous gradually. The reaction mixture was cooleddown and then further heated at 150° C. in a vacuum oven another 19hours.

Samples were taken from the reaction mixture after 2 hours (A), 5 hours(B) and 24 hours (C) and the molecular weight was calculated using GPCusing polystyrene standards in THF. FIG. 9 is a plot of GPC data forsamples A, B and C.

Reaction time Molecular Molecular Degree of Retention (hours) Weight,M_(n) Weight, M_(w) Polymerization Time A 2 4430 9630 62 20.3 B 5 735018100 102 19.3 C 24 18800 37500 261 18.3

Note that after 24 hours the degree of polymerization is ˜250 units, farbelow the polymerization conversion achieved in the inventive processwhich uses a thin film polymerization/devolatilization device.

Other than in the examples herein, or unless otherwise expresslyspecified, all of the numerical ranges, amounts, values and percentages,such as those for amounts of materials, elemental contents, times andtemperatures of reaction, ratios of amounts, and others, in thefollowing portion of the specification and attached claims may be readas if prefaced by the word “about” even though the term “about” may notexpressly appear with the value, amount, or range. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains errornecessarily resulting from the standard deviation found in itsunderlying respective testing measurements. Furthermore, when numericalranges are set forth herein, these ranges are inclusive of the recitedrange end points (i.e., end points may be used). When percentages byweight are used herein, the numerical values reported are relative tothe total weight.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10. The terms “one,” “a,” or “an”as used herein are intended to include “at least one” or “one or more,”unless otherwise indicated.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

While this invention has been particularly shown and described withreferences to most preferred embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe made therein without departing from the scope of the inventionencompassed by the appended claims.

1. A method of making a polymer or copolymer, the method comprisingevaporating water as it is formed during condensation of ahydroxy-carboxylic acid polymer as it traverses a surface of a thin filmevaporator.
 2. The method of claim 1, where the thin film evaporatorcomprises a thin film polymerization/devolatilization device.
 3. Themethod of claim 2, where an extruder is in fluid communication with thethin film polymerization/devolatilization device and the effluent of theextruder is the poly hydroxy-carboxylic acid polymer or effluent of theextruder is recycled to the thin film evaporator.
 4. The method of claim3, where the extruder is a twin screw extruder.
 5. The method of claim1, wherein the hydroxy-carboxylic oligomer is derived from the monomergroup consisting of glycolic acid, D-lactic acid and/or L-lactic acid,D-malic acid, L-malic acid, citric acid, L-tartaric acid and D-tartaricacid and mixtures thereof.
 6. The method of claim 5, wherein thehydroxy-carboxylic acid is D-lactic acid and/or L-lactic acid.
 7. Themethod of claim 1, where at least a part of the thin film evaporatoroperates at a temperature of 100 to 260° C.
 8. The method of claim 1,where at least a part of the thin film evaporator operates at a pressureof 0.0001 torr or lower.
 9. The method of claim 2, where prior totransferring the poly hydroxy-carboxylic acid to a thin filmpolymerization/devolatilization device or during operation of the thinfilm polymerization/devolatilization device a catalyst deactivatorand/or stabilizer agent is added.
 10. The method of claim 2, wherecyclic dimers derived from hydroxy-carboxylic acid is less than 5 weightpercent based on the total mass of the hydroxy-carboxylic monomers,oligomers and polymers.
 11. The method of claim 2, where an aliphatic oraromatic dicarboxylic acid and an aliphatic or aromatic diol is areadded just prior to transferring the poly hydroxy-carboxylic acid to thethin film polymerization/devolatilization device.
 12. The method ofclaim 11, where the mole ratio of the aliphatic or aromatic dicarboxylicacid to the aliphatic or aromatic diol is 0.95:1 to 1.05:1.
 13. Themethod of claim 11, where the mole ratio of the sum of the aliphatic oraromatic dicarboxylic acid and the aliphatic or aromatic diol to thehydroxy-carboxylic acid monomer of the poly hydroxy-carboxylic acid is0.1 or less.
 14. The method of claim 11, where the mole ratio of the sumof the aliphatic or aromatic dicarboxylic acid and the aliphatic oraromatic diol to the hydroxy-carboxylic acid monomer of the polyhydroxy-carboxylic acid is 0.05 or less.
 15. The method of claim 1,where the polymerization catalyst is selected from the group consistingof protonic acids, H₃PO₄, H₂SO₄, methane sulfonic acid, p-toluenesulfonic acid, polymerically supported sulfonic acid, metals, Mg, Al,Ti, Zn, Sn, metal oxides, TiO₂, ZnO, GeO₂, ZrO₂, SnO, SnO₂, Sb₂O₃, metalhalides, ZnCl₂, SnCl₂, SnCl₄, Mn(AcO)₂, Fe₂(LA)₃, Co(AcO)₂, Ni(AcO)₂,Cu(OA)₂, Zn(LA)₂, Y(OA)₃, Al(i-PrO)₃, Ti(BuO)₄, TiO(acac)₂, (Bu)₂SnO,Sn(II)octoate, Li carbonate, Zn diacetate dehydrate, Titetraisopropoxide, potassium carbonate, tin powder, solvates of any ofthese and mixtures of any of these.
 16. The method of claim 2, where atleast a part of the thin film polymerization/devolatilization deviceoperates at a pressure of less than about 0.001 torr.
 17. The method ofclaim 2, where at least a part of the thin filmpolymerization/devolatilization device operates at a pressure of lessthan about 0.01 torr.
 18. The method of claim 2, where at least a partof the thin film polymerization/devolatilization device operates at apressure of less than about 0.1 torr.
 19. The method of claim 2, whereat least a part of the thin film polymerization/devolatilization deviceoperates at a pressure of less than about 1 torr.
 20. The method ofclaim 1, further comprising branching or cross linking the polyhydroxy-carboxylic acid.
 21. The method of claim 20, wherein a branchingor cross linking agent is utilized to cross link the polymer and thecross-linking agent selected from the group consisting of5,5′-bis(oxepane-2-one)(bis-8-caprolactone)), spiro-bis-dimethylenecarbonate, peroxides, dicumyl peroxide, benzoyl peroxide, unsaturatedalcohols, hydroxyethyl methacrylate, 2-butene-1,4-diol, unsaturatedanhydrides, maleic anhydride, saturated epoxides, glycidyl methacrylate,irradiation and combinations of these.
 22. The method of claim 1,wherein the poly hydroxy-carboxylic acid is blended with a secondpolymer either when the poly hydroxy-carboxylic acid is transferred tothe thin film polymerization/devolatilization device or after the thinfilm polymerization/devolatilization device.
 23. The method of claim 22,wherein the second polymer is selected from the group consisting ofpolyglycols, polyvinyl acetate, polyolefins, styrenic resins,polyacetals, poly(meth)acrylates, polycarbonate, polybutylene succinate,polyesters, polyurethanes, natural rubber, polybutadiene, neoprene,silicone, other poly hydroxy carboxylic acids, and combinations ofthese.
 24. The method of claim 1, comprising combining the polyhydroxy-carboxylic acid with fillers.
 25. The method of claim 24,wherein the filler is selected from the group consisting of silicates,layered silicates, polymer and organically modified layered silicate,synthetic mica, carbon, carbon fibers, glass fibers, boric acid, talc,montmorillonite, clay, starch, corn starch, wheat starch, cellulosefibers, paper, rayon, non-woven fibers, wood flours, whiskers ofpotassium titanate, whiskers of aluminum borate, 4,4′-thiodiphenol,glycerol and mixtures of these.
 26. The method of claim 1, furthercomprising combining the poly hydroxyl-carboxylic acid with a dye orpigment.
 27. The method of claim 26, wherein the dye is selected fromthe group consisting of blue3, blue 356, brown 1, orange 29, violet 26,violet 93, yellow 42, yellow 54, yellow 82 and combinations of these.28. The method of claim 1, further comprising combining the polyhydroxy-carboxylic acid with a fragrance.
 29. The method of claim 28,wherein the fragrance is selected from the group consisting of wood,evergreen, redwood, peppermint, cherry, strawberry, peach, lime,spearmint, cinnamon, anise, basil, bergamot, black pepper, camphor,chamomile, citronella, eucalyptus, pine, fir, geranium, ginger,grapefruit, jasmine, juniper berry, lavender, lemon, mandarin, marjoram,musk, myrrh, orange, patchouli, rose, rosemary, sage, sandalwood, teatree, thyme, wintergreen, ylang ylang, vanilla, new car or mixtures ofthese fragrances.
 30. The method of claim 28, wherein the fragrances arecombined with the poly hydroxy-carboxylic acid in an amount betweenabout 0.005% by weight and about 20% by weight.
 31. The method of claim1, wherein converting further includes blending the polyhydroxy-carboxylic acid with a plasticizer.
 32. The method of claim 31,wherein plasticizer is selected from the group consisting of triacetin,tributyl citrate, polyethylene glycol, acetic ester of monoglyceride,diethyl bishydroxymethyl malonate and mixtures of these.
 33. The methodof claim 9, where the stabilizing agent is selected from the groupconsisting of anhydrides, phosphites, polycarboxylic acids, polyamines,silica, functionalized silica, alumina, aluminosilicates, clays,functionalized clays and mixtures of these.
 34. The method of claim 33,where the polycarboxylic acid is a poly methacrylic acid.
 35. The methodof claim 9, comprising removing the deactivated/stabilized catalystprior to, during or after the thin film polymerization/devolatilizationdevice by a filtration device.
 36. The method of claim 9, comprisingremoving the deactivated/stabilized catalyst by a filtration device. 37.The method of claim 36, where the filtration device is in fluidcommunication with the thin film polymerization/devolatilization device.38. The method of claim 2, where at least a part of the thin filmpolymerization/devolatilization device operates at a pressure of fromabout 0.0001 to about 100 torr.
 39. The method of claim 2, where atleast a part of the thin film polymerization/devolatilization deviceoperates at a pressure of from about 0.001 to about 50 torr.
 40. Themethod of claim 2, wherein the hydroxy-carboxylic oligomer is derivedfrom the monomer group consisting of glycolic acid, D-lactic acid and/orL-lactic acid, beta-hydroxy beta-methylbutyric acid,4-hydroxy-4-methylpentanoic acid, hydroxybutyric acid, 2-hydroxybutyricacid, beta-hydroxybutyric acid, gamma-hydroxybutyric acid3-hydroxyisobutyric acid, 3-hydroxypentanoic acid, 3-hydroxypropionicacid alpha, beta, gamma or delta-hydroxyvaleric acid and mixturesthereof.